PEST AND DISEASE CONTROL
A PESTS Rukandema et. al. (01896) reported the
1 General crop protection reports findings obtained from a farm survey from
General reports appraising crop protection in Mwala location in lowlands Machakos.
Kenya have been written since early 1970's. Although farmers viewed insect pests as
They are reported here in a chloronological serious, they did not protect the crops from
order. pests. Anon (241357) reported on the
Sasser (244968) wrote a multidisciplinary study physiology, ecology and control of insects and
report on crop protection referring to Kenya and other arthropod pests. Seif (19121) reviewed
some other countries in Africa. Anon (230359) the use of biotechnology in crop protection.
wrote a report on entomology and pest control The negative effects of biotechnology were
research and services in Kenya. Tait and discussed and the need for a government
Napompeth (100038) discussed farmers' policy on guidelines for use of biotechnology
perceptions and practices on management of products was emphasized. Involvement of the
pests and pesticides. Harris and Scott private sector in tissue culture on commercial
(243771) discussed the international basis for mass propagation of disease free
perspective of crop protection information. planting material was suggested. Specialized
Anon (229902) produced a guide to pest and manpower training in refined disciplines of
disease control for wheat and barley growing biotechnology was recommended.
areas of Kenya. FAO (229356, 228252) gave a
report on action programme for improved plant 2 CROP INSECT PESTS AND THEIR
protection in Kenya and other East African CONTROL
countries. Ingram (243510) wrote a report on
survey of plant protection in Kenya. Buyckx 2.1 COFFEE
(229121, 24403) reported on crop protection in
dryland farming. Beets (228657) wrote on Ongute (20478) discussed possible problems
aspects of traditional farming systems in of pest control arising from intensification of
relation to integrated pest managment. Kibata coffee growing in Kenya. Ongute (01787)
(201491, 22033) and FAO (202523) discussed discussed the general pest sistuation on Kenya
the issue of strengthening of plant protection in coffee estates. Charwdhry (21874) reported
Kenya. Malaret and Ngoru (240756) discussed that addition of insecticide and foliar nutrient
on farmer knowledge of termites in Machakos sprays had no significant effect on the dieback.
District. Lako (11266) tested whether IPM
menu was economically viable in Oyugis and Waikwa and Macharia (15465), Waikwa and
Kendu Bay division of South Nyanza District. Dooso (06497), Dooso and Waikwa (19625)
and Waikwa (02839) investigated coffee pests significantly different for treatments with 2
and their natural enemies in coffee estates. larvae/plant, 10 larvae/plant and the infestation
They found that parasite population of by the second generation. Delobel (238266)
leafminers coincided with that of leafminer moth described a technique for evaluating damage
population. The predators for coffee pests caused to sorghum by Atherigona soccata in
included Arenea, Coccinellid, Manlids, Kenya. Ampong-Nyaiko (32562) investigated
Chrysops, Macrorphalis and Acuta. Leafminer the role of residue management in IPM strategy
parasites were Argeniaspis spp, A. ritchieis, C. in sorghum. The least number of stemborers
lepelleyi, C. varieteis, P. leucoptera, P. was recorded in the ploughed treatment with
Caffeicola, A. bordagei. They also investigated stubble removed. The number of thrips was
the effects of insecticidal spray (different levels) significantly lower in the nontilled plots and
on major coffee pests and their natural highest in ploughed plots with stubble removed.
enemies. Thuo and Kamau (17994) analyzed Dogget and Jowett (17555) outlined three
169 samples of simithion, Delan, Lebaycid, approaches used for breeding sorghum for
Dursban and Omethoate and found that 19 resistance to birds.
samples were substandard.
2.2 MAIZE Hastle (20789) found out the period during the
growth of the crop that is profitable to give
Graham (17860) controlled Schizaphis protection against pests. In laboratory tests
graminum and Rhopalosiphus maidis by use of BHC and Malathion showed promise as bait for
Malathion and Diazinon. Firempong et. al. Dysdercus spp. Hastle (15536) noted and
(200375, 202595, 238294) investigated Chilo described some forms of abnormalities on
partellus oviposition, larval feeding and cotton.
development of different maize cultivars. The
plant characters that appeared to influence Wheatley and Crowe (9572) evaluated
oviposition included plant excudates (as the insecticides for control of pests on cotton.
moth diet) and leaf surface trichomes. The Seven applications of 3:10:10 dust at seven day
quality of the excudates from the different intervals was the most effective. Anon (9045)
genotypes appeared to influence moth showed no signifant difference between BHC
fecundity and lifespan, while trichomes and DDT dusts on control of cotton pests.
appeared to influence selection of oviposition Neither dusts gave satisfactory control of spider
site. Plant growth characteristics rather than mites. Bretell (21910) showed that 10 spays of
the level of resistance appeared to be the major Carbaryl based on insect counts gave a
factor influencing the movement of the larvae considerable improvement in yield and grade of
within plants. Anon (34265) described how to seed cotton compared with the fixed regime of
select maize cultivars resistance to Chilo five sprays. When the cost of the insecticide
partellus. Ampong-Nyarko et. al. (32560) used in the fixed regime was deducted from the
recorded the lowest incidence of maize return, the profit was less than when no sprays
stalkborer in the intercrop compared to maize were applied. Bretell (22007) showed that
trap crop and maize monocrop. Odulaja and more expensive spraying machines did not
Nokoe (33191) described a mathematical produce, significantly higher yields of seed
model for classifying maize varieties. cotton than in expensive sprayers. Waturu and
Njoka (16714, 16712) evaluated 15 insecticides
2.3 SORGHUM using electrodyn and ULV applicators. The
electrocyn formulations had the best control of
Dogget and Manjisu (12556) evaluated DDT, red spider mites. The African bollworm was
Dimecron, Piptesox, Menazon and Thiodan for best controlled by ULV application of Ambush
control of shootfly in Serena and white applied at 1.0l/ha. Lygus spp was best
wheatland variety. Menazon applied weekly controlled by Karate applied with electrodyn.
afforded the best control of shootfly in both
varieties. Overman and Muhwana (20) 2.5 COWPEAS
evaluated sorghum materials for resistance to
sorghum shootly. Pathak and Shehu Reddy Otieno et. al. (21906) investigated the chemical
(21600) did crop loss assessment in sorghum. aspects of cow pea resistance to the pod borer,
They found that grain yields were not Marura testulalis. They showed the presence
of more active components in the extracts of
the resistant cowpea cultivar TVU 946. Crowe (232029), Gonzalez (232024), Berg
Firempong (13627) examined the role of non (232038) discussed control of locust and
preference and antibiosis in cowpea resistane research needs on locust. Khasimuddin
to aphids. the non preferene studies revealed (230988) reported on the courtship and mating
that the cultivar 1T82, D-812 and ICV 12 were behaviour of the African armyworm,
the least preferred ones for colonization and Spodoptera exempta.
TVU 946 and IT 8D - 113 were the most
preferred. The antibiosis tests showed that ICV 4 PESTICIDES
was the most resistant cultivar. ICV I was the
most susceptible. Mckinly (04552, 04554) determined the
magnitude and cause of phytotoxicity of BHC.
2.6 HORTICULTURAL CROPS He also reported on the efficacy of Dieldrin,
DDT and Toxaphene on Dysdercus
Richard et. al. (230663) discussed horticulturla nigrofasciatus. Bullock (05264) examined the
research and development in the arid zones of effect of hand application of DDT on maize and
Africa. Wheatly (17667) controlled soft scales, its phytotoxicity. Anon (243775) discussed the
Coccus hesperidum more effectively by toxicity of Aldrin to Kenya farmers. Jensen et.
Diazinon than by Malathion. Chlorobenzillate al. (201715) evaluated the need and role of
effectively controlled all stages of citrus red pesticides in Eastern and Southern African and
spider mites. Beijea et. al. (228399) produced current pesticide situation in relation to
a horticultural crop protein handbook. manufacturing, management, utilization and
marketing in the region. He pesticide legislation
2.7 BEANS in the region and the problem associated with
insufficient foreign exchange. Also, he looked
Anon (33446) evaluated insecticides for control at the health and environmental concerns of
of bean flower thrips. Diazinon at the rate pesticide use and whether farmers and farm
1.0l/ha gave the best control of bean flower workers knew enough to protect themselves.
thrips followed by Radan II, Nomolt II, Cascade
II, Diastar II, Nomolt I, Redland I, Diastar I and 5 PESTICIDE RESIDUES
Cascade I in that descending order of activity.
Mutai (02682) investigated the effect of washing
28. RICE the capsicums on the fate of pesticide residues.
Washing reduced residues of DDT and
Khan (20215) investigated weeds as alternative Fenitrothion on capsicums. Koeman (231592)
hosts for rice leaffoders. For some 6 weed gave some suggestions for future environment
species the proportion of C. medinalis settling in developing countries.
on them did not differ significantly from those
settling on the resistant and susceptible checks. 6 ANTIFEEDANTS
2.9 BARLEY Hassanali et. al. (14617) Torto (09340), Lwade
et. al., (12059), Lwande et. al. (237503),
Anon (10586) found that aldrin and dieldrin Lwande et. al. (239044), Lwande (21266) have
seed dressing, phosphamidon and Rogor investigated antifeedant from Harrisonia
sprays as effective on pest infestation on abyssinica, Teclear trichocarpa, Terphoria
barley. hildbrandtii. Hassanali et al (32888) reported
on sex pheromone of Chilo partellus,
aggretation pheromone and feeding
semiochemicals of Cosmopolites sordidus,
2.10 BANANAS locust semiochemicals, cowpea odours on
Anon (32091) investigated the effect of banana
weevil on bananas and found high infestation of 7 STORAGE PESTS
the pest at the Coast and Nyanza Provinces.
Ashman et. al. (12551) found that pyrethrins
3 DESERT LOCUST AND synergized with piperomyl butoxide gave good
ARMYWORMS control of Sitophilus zeamais, Tribolium
casteneum and Cadadra cautella. Mixtures of citrus pests and weeds. Waiyaki (17541)
pyrethrin and Malathion were more effective evaluated Bacillus thuringiensis against larva of
than Malathion dust along. De Lima et. al. Busseola fusca. The larvae mortality was high
(13740) conducted surveys in storage premises and pupation did not occur in any of the larvae
in Nairobi, Mombada, Nakuru and other parts of that survived the treatment. Rens (18362)
the country to establish the extent of evaluated DDT, Dipen evaluated Bacillus
infestations by different storage pests and to thuringiensis against Heliothis armigera and
devise ways and means of controlling these Cosmohila larvae on cotton. He found that
pests. Imported cargo provided the bulk of the thuricide and Dipen were effective on spiny
comodity destroyed due to heavy infestation. bollworm and American bollowrm. Otieno
De Lima (236898) evaluated Lindane (14056) evaluated a nematode, Panagrolaimus
resistance in field status of Sitophilus zeamais. sp for control of crop borers. Borer larvae died.
De Lima et. al. (13744) compared Actellic, The nematode activity was temperature
Gardona and Bromaphos with Malathion. dependent. Ogwang and Mathews (237535)
Actellic gave the best control of the storage investigated electrostatic application of B.t. on
insect. Brussel sprouts. Improved coverage of the
lower surfaces of electrostatically sprayed
Mutambuki (12731) carried out storage and sprouts plants was observed. Mulaa et. al.
infestation control surveys. Infestation levels in (33443) identified Apanteles sesamiae,
the stores were generally light to medium. Diaperasticus erythrocephala, Cheilomenes sp
Pests and their frequency on various and Componotus rafoglacus parasitoids of
commodities were recorded. Mutambuki et. al. Busseola fusca. Cock (18992) recorded that
(16620) carried out storage and infestation orius spp, Anthocorid bugs, Pheidole sp and
control surveys. The insects found during the Mymicaria sp, Campoltis chlorideae, Uchida,
surveys in order of decreasing frequency were: Aphanteles and Hyposotor didymetor were the
Tribolium sp, Sitophilus spp, Sitotroga sp, most important biological control agents of
Cryptolestes sp, Gnathocerus sp and African bollworm.
Demestes sp. Kimondo et al (32903) carried
out storage and infestation control surveys.
Ephestia spp in ware houses was rated as the 9 NEMATODES
most frequent occuring, followed by Tribolium,
Sitophilus and Rhizopertha. Muhihu (02665) Anon (13728) showed that fumigation of coffee
carried out storage and infestation control seedlings using D-D had increased dry weight
survey. The commonest insect were Tribolium of total leaf area and three fold increase in the
castenaum and Sitophilus zeamais. length of the tap rot. Firman (15287) showed
marked growth stimulation of coffee seedlings
Giles (31623) investigated post maturity grain with DD fumigation. The root systems were
losses in the field in Western kenya. well developed in treated coffee seedlings.
Microorganisms, particularly moulds, infected Nematode found around plant roots consisted
the grains causing weight loss and rotting. of Dorylamoidea. Arango et. al. (237305)
Grain discolouration and weathering occurred. evaluated 46 cofea arabica selections for
During the post-mature period about ten resistance to Meloidogyne spp. Selections
percent of the grains in upright plants were which showed resistant plants were M-205,
damaged and four percent actually lost. It was Rume Sudan, N-39, R-3, SL-6, Ainamba
recommended to harvest at 30 percent babaka Kaffa, Kabare 18. Anon (16971)
moisture content rather than at 15 percent. showed that post-planting fumigation with
There was still no hybrid available with good DBCP (Nemagon) increased pineapple yield.
enough husks characteristics to recommend to Odhiambo (03697) showed that in soil samples
the farmer in order to reduce field damage from various parts of the country, Meloidogyne
drastically. sp was the most prevalent and appeared in 44
percent of the sample analysed followed by
8 BIOLOGICAL CONTROL OF INSECT Scutellomeve spp, Ditylenchus sp and
PESTS Helicotylenchus sp.
Anon (237675, 242038, 238284, 242059) B DISEASES
reported on biological control of cassava pests,
coffee pests, sugarcane borers, mango pests, 1 GENERAL REPORTS ON DISEASES
quality and yield. All the spray treatments
Gitau (01014) reported on disease in Nyanza. reduced coffee bean size, the proportion of
The most serious diseases were early and late grade 'A' ranging from 32 to 37 compared with
blights of potato and brown spot of passion 43 for the unsprayed coffee.
plant. Anon (11953) investigated the
pathogenic fungi and bacterial disease that may Cood=k and Mulinge (15762, 03074, 236662)
have been carried internally or on the surface of surveyed on the rates of fungicides and spay
the seeds of beans, rice, soybeans, toamato, timing by coffee growers in Kenya. They found
cowpeas and maize. Odhiambo (14976) that at low altitudes the short rain sprays had no
analysed plant materials and soil sample for effect on crop yield. At high altitudes, the short
disease arganisms and nematodes. Spots, rots rains sprays increased yields upto 60 percent in
and wilts were the most prevalent disease. crop from the October and March flowerings.
About 71% of the diseases were caused by They found that after 50mm of rain, 10 percent
fungi, bacteria, nematodes and viruses. of copper was washed off the trees, and 9
Damage was also observed attributed to insect percent tottal Captafol was washed off after
pests, pesticides, environmental factors and 12.5 mm of rainfall. After heavy rainfall,
nutrient imbalance in the soil. Kanyagia therefore, conditions would be created that
(10662) screened vegetables, field crops and favour the spread of CBD. Captafol sprays in
grasses for Melodoigyne hapla and found that October and November were only likely to be of
members of graminae family were resistant to economic benefit if applied to trees bearing a
attack. Anon (20545) reported on sugar cane major crop in the "green berry stage" as this
smut, Pseudomonas solanaceam, identification would result from a major flowering from the
of physiological races of cereal rusts, breeding previous April. Mulinge (02894) compared
for rust resistance in wheat and rice yellow aerial spraying and conventional hand spraying
mottle virus disease of rice in Kenya. method. Both spraying techniques controlled
CBD effectively. Fungicide redistribution when
2 CROP DISEASES sprays were applied during periods of heavy
rainfall and the use of stickers with benomy
2:1 COFFEE appeared to be advantageous in the control of
Bayner (207121) tested copper Bordeax,
Burgundy, Tulisano and Lime sulphur to Aduayi and Gitau (03020) recommended that
prevent leaf fall in coffee. There was no leaves should be washed off copper before
significant response to either copper or non- copper determination in the leaves. Okioga
copper. Anon (14188) found that low volume (21886) recommended Antracol, Captafol,
application of high copper fungicide Sicarol + Captofol, Perenox + Capatafol, Sicarol
concentration was significantly better from the + Bavisitn and Siracol + derasol in areas where
control for reduction of leaf fall at Kiambu. CBD and leaf rust are significant problems.
Gregory (05321) discussed the principle used in Maithia (236295) reported on a simple method
the sprayer in saving time mixing chemicals, of weighing fungicides for use with knapsack
marking out plots and, spraying individual plots. sprayers to control Hemileia vestatrix and
Anon (13972) investigated spray timing and Colletotrichum coffeanum. Rijo and Cook
volume for reduction of leaf fall in coffee at Kisii. (237869) investigated the connection between
There were no volume and high volume leaf spot and rust on Coffea arabica. Msabaha
treatments. (05352) evaluated the efficacy of 50 percent wp
copper formulations for the control of CBD.
Griffiths et. al. (486) found that extended Coffee sprayed with copper Nordox, Recop,
spraying in July of cofee with captafol gave Microscop-50, Funguran gave yields
excellent control of CBD diseases. Captafol comparable to those from Captafol. Chemically
was generally superior to copper in CBD treated plots gave significantly better yields than
control. Anon (04119) found that application of the unsprayed plots.
cuprous oxide affected the composition of Mn,
Fe and Cu in the leaves of the sprayed trees Maithia (237165, 237319, 21512) compared
and decreased these trace elements. Mitchell some fingicide application equipment on coffee
(15552, 06094) investigated the effects of in Kenya. The physical and mechanical factors
insecticides, fungicides and foliar nutrients of which govern the efficacy of spray machines
coffee yield. The sprays increased coffee were described in relation to the wheelbarrow
power spray, MP60, Polijacto motorized Dickinson and Lepp (237090) showed that
knapsack mist blower and the PTP manually coffee bushes that received excess copper
perated hydraulic knapsack sprayer. Motorised showed a variety of foliar disorders, reduced
knapsack mist blower, mannually operated extension of shoots, increased infestaion by
hydralic knapsack and high pressure footbord leaf mining insects and decreased fruit
sprayer were found suitable for fungicide production. These results were related to
application. present and projected rates of copper fungicide
application to coffee, and the possible
Anon (11554) evaluated tank mixtures using
Anon (9503) found that standard spay reduced rates of organic and copper fungicides
programm for Bacterial Blight and CBD using for control of CBD. Tank mixtures of
copper Nordox sprays applied at 2 weeks recommended organinc fungicides and copper
intervals during the first half of the year, gave better control than the organic fungicides
followed by 3-week intervals thereafter giving on their own. Wapakala (15159) investigated
14 spays per year, was as good as the spays copper spray timing in coffee. The best copper
based on rainfall regim. spraying timing was one that applied in January
to March then June, July. Reponses to copper
Javed (9801, 06098, 17255, 20708) found that sprays were large and significant. Schedules
the plots that received spray of Captofol timed for additional sprays in May, October and
according to rainfall patterm had less CBD than November resulted in higher yields.
the current recommended anti-CBD
programme based on fixed calendar schedule. 2.2 MAIZE, BEANS, RICE, WHEAT
Flexible spay programme depended on rainfall
pattern was proposed for high altitude areas. Rheenem et al (229673) showed that beans
Plots receiving spays of tank mixture of Aptaful grown in association with maize had less
+ Perenx and Peronox Captafol Delan + perens incidence of halo blight, bean common mosaic,
applied after every 100mm of rainfall (5 sprays anthracnose, common blight, scab, phoma,
between February and July 1981) controlled mildew, bollworm and angular leaf spot. Anon
CBD significantly better than the standard spray (12117) showed that the growth stage 1
programm (6 spays applied between February (seedlings has two leaves) was very
and July 1981). Captefol and Delan sprayed susceptible to Pseudomonas phaseolicola
alone did not give good control of CBD and followed by the young pods in growth stage VIII
gave lower yields. He found that the rate of (production of mature seeds in the pods).
brown blight infection in high altitude was not Resistance to the disease appeared to be
lowered in spite of spays with benzimidazole governed by a single recessive gene. Anon
fungicide during dry periods. (17407) reported that halo blight (Pseudomonds
phaseolicola) was found to be one of the widely
Kairu (19455, 19630) tested chemicals for distributed disease in Kenya and its attack on
control of Bacterial Blisht and CBD on coffee. beans in early stages resulted in low yields.
Spray of Koade 101 applied at the beginning
mid-March 1983 at 2 week interval gave Anon (12149) assessed diseases at the Ahero
effective control of bacterial Blight during the Irrigation Scheme. Among the diseases
first infection peak. All copper spray schedule recorded were Rice yellow mottle virus, Brown
gave a significant control of Bacterial Blisht and spot, leaf blast and sheath blight.
CBD. Berdeaux mixture and Kocide effectively
control bacterial diseases on coffee. Kulkarui and Sheffield (12387, 12384)
investigated abnormal conditons in wheat and
Masamba and Mwangombe (19475) tested hybrid bulbila. They inoculated Tsichodorus
tank mixture of the foliar feed and fungicide for spp with leafhoppers but found the plants were
CBD control. Captafol 80 percent WP alone healthy. Anon (13347) attempted to transmit
and in tank mixture with stintol controlled CBD condition of malassess grass in wheat varieties
significantly. but no positive results were obtained.
Pereira (20071) discussed some possible effect 2:3 SUGARCANE
on intensification on spray application in coffee.
Nyangau and Osoro (33528) evaluated five infestan, Corynebacterium michiganenze,
fungicides for control of pineapple disease of Alternaria solani, Septoria hycopersici, Blossom
sugarcane caused by Ceratocystis paradoxa. end rot and root knot nematodes. Whittle and
Aretan and Tillexc allowed the highest Seif (228556) reported on Greening disease of
germination of sugarcane followed by Benlate. citrus in Kenya. Anon (13672) reported on a
However, there was no influence of fungicides survey of banana disease on Muranga, Nyeri,
on the tillering capacity of sugarcane. Wawire, Embu and Meru Districts. In all the districts,
et al (01196) reported on survey covering leaf spot caused by Pseudocercospora sp and
ratooning, methods of weeding and smut Phoma jelygana were recorded. Armillaria
control methods in Nyanza sugar belts (Mwani, mellea on bananas was recorded in the lower
Chemitili, Muhoroni). ares of Meru district. Root rot (Xylari sp) and
Darotymes microsporus were reported for the
2:4 PINEAPPLE first time causing severe damage on pears in
Limuru areas. Anon (09557) showed that
Templer (12187, 12191) showed that Bayfidan was effective in control of Black
fumigation with DD, and Nemagon in pre- sigatoka on bananas. Anon (17474) showed
planting application on pineapple tended to that plants grown at an altitude of 8,500 ft
improve yield and fruit grade. However there appeared to have maintained their freedom
was no statistical evidence in favour of from virus. Anon (18643) observed curcubits
fumigation and the responses were also infected with Peromospora parasitica during the
uneconomical. Waithaka (19075) found there cold and rainy months at Thika.
were no significant difference between
polythene mulch and soil fumigation with 2:8 TREES
nemogan in the yield of pineapple fruits.
Mwangi and Seif (03235) reported on
2:5 PYRETHRUM investigations on wilt of Leucaena
leucocephala. Rotten roots and mycelia
Wambugu (18422) investigated wilting beneath the back were noted. Fusarium was
conditions in pyrethrum. Isolation made from isolated from the root system, while
the affected parts yielded a number of fungi and Phytophthora was isolated from the bark.
nematodes but pathogencity studies showed
negative results. C PLANT QUARANTINE
Ondieki (34025,) also investigated wilting Sheffield (01317, 0593, 00760) discussed the
conditions of pyrethrum. It was found that low history of plant quarantine in East Africa.
soil PH (below PH5) and levels of calcium, Various ways of minising risks of introduced
phosphorous and nitrogen were predisposing pests was discussed. It was stressed that the
factors at the Eldoret pyrethrum nursery leading precautions suggested of certificates to be
to invasion by Fusarium and other fungi. He obtained, treatments to be given, tests to be
recommended remedial measures to raise the devised and prohibitions to be imposed are
level of soil as well as improvement of the dependent upon a knowledge of the disease to
nutritional status of the soil. which each imported species is susceptible and
world distribution of the pathogen. Ojero
(12202) discussed the importance of plant
inspection to Kenya's agriculture. It was
mentioned that exotic pests could cause great
2:6 TEA hazards after establishing themselves by
adjusting to the naturally prevailing
Green (13338) noted that granular formulations environmnetal conditions of their new habitat.
(eg Tridipam) as soil fumigant for mixing with
soil were the best for use in new plantings. Kechecheba (236588) discussed some
horticultural aspects of plant quarantine.
2:7 HORTICULTURAL CROPS Luisoni et. al. (231613) reported on screening
and quarantine of cassava from East Africa
Anon (18643) reported the infection of curcubits mosaic disease. Mathenge (234702)
by Peromospora parasitica. Seif et al (10657) discussed the role of the National Seed Quality
reported infection of tomato by Phytophthora Control Services.
Robinson (17816) reported on observations of
Rajak (234514) compared plant quarantine "Green Vein Chlorosis" on coffee leaves.
management in India, Kenya, Australia and Spraying leaves with Ferrous sulphated gave a
America. Anon (301172) discussed plant positive response. It was conclude that the
quarantine services in Kenya on potatoes. "Green Vein Chlorosis" was due to lack of
Waite et al (32989) discussed the role of avialable iron necessary for adequate leaf
quarantine on the importation of potato metabolism.
germplasm. Peregrine reported on a suvery on
plant quarantine in Kenya, Tanzania, uganda, Jones (17784) showed that copper sprays
Ethipia and Somalia. Olembo (235238) reduced leaf fall in coffee and sprayed trees
discussed seed health testing at the plant suffered less die-back, thus were able to bear a
quarantine station at Muguga. Anon (18928) large crop.
reported on virus indexing of Solanum
tuberosum imported from Lima, Peru. 701
Wormer (06649) described various
varieties were released to vrious interest parties
abnormalities on coffee leaves, flowers and
for further evaluation tests. Okioga (21423)
stems. Hot and Cold conditions caused the
discussed the use of biotechnology for
improvement of cassava yams and plantain.
Okioga (200110) discussed phytosanitary Sheffield (12442, 13471) described the stem-
services in Africa. Okioga (200339) discussed fitting conditions observed in young arabica
the role and responsibilities of plant quarantine coffee trees and reviewed possible causes of
services in Kenya. the conditions.
Kahn (200299) discussed plant quarantine and Robinson (15320) determined the cause of
the global transfer of plant genetic resources. amber beans (yellowish beans) of coffee. It
Okioga (04220) discussed application of was noted that one source was from mature
biotechnology in plant quarantine procedures. trees suffering from iron chlorosis. Robinson
(15323) determined micronutrient levels for
Ologa and Mavogo (03478) gave importation of leaves sprayed with a liquefied sea weed
plant materials received by the plant quarantine preparation. Leaf managanese content was
at Muguga in 1990. Okioga et al (03965) and increased by the spray. Robinson (15335) did
Olago and Mavogo (03409) reported on seed leaf analysis from coffee suspected of being
health testing at plant quarantine station, unbalanced in its nutrition and showing
Muguga. Anon (18925) reported on field deficiency symptoms. Magnesium unbalance
inspection of maize, wheat, barley, sunflower, was typical in many coffee areas white zinc
grasses and bean seeds. value were low in leaf samples collected under
Waage (200717) disicussed quarantine of
exotic insect control agents for introduction Firman (15311) investigated "Stem-pitting"
against larger grain borer in Africa. Anselme symtoms and condition of coffee plants. While
(229241) discussed quarantine protection cultural conditions affected the development of
against seed-borne (plant) diseases. the symptoms they did not appear to unitiate
these symptoms. Symptoms were found to
NUTRIENT AND NUTRIENT DISORDERS start in the very young nursery plants. Severely
affected plants did not show loss of vigor or
1 COFFEE yield apart from tree deformation and possible
secondary invasion of microorganisms.
Michori et al (237152, 21151, 19742) reported
on soil and leaf analysis from samples sent to Anon (17514) studied the influence of weed
Ruiru by farmers. Anon (17967) found that growth on nitrogen in the soil and coffee leaf.
carbide spray altered physiological There was consistently higher leaf nitrogen
development of the coffee trees and had content in the absence of weed growth which
flowering generally retarded. The sprayed suggested active competition between weeds
trees, however, carried a heavy crop and dense and coffee for the naturally available soil
foliage and no leaf fall at the end of the year. nitrogen supply.
Anon (13705) analysed leaves showing by the die-back. Boron gave slightly better
phosphate deficiency and gave the levels of the protection in months with high rainfal.
element. The presence of mulch in coffee
significantly increased the leaf nitrogen levels in Kimeu (420) establisehd the occurrence of
the leaves during net period. deficiency symtpoms and the actual nutrient
composition in deficient coffee leaves. The
Wapakala (15156) studied the effect of copper elements investigated included N, P, Mg, Fe
sprays on coffee leaf retention. The results and Zn in the case of severe, mild and normal
showed that trees sprayed with copper cases of leaves.
according to recommended schedule had more
leaves on their secondaries than unsprayed Kumar (237348, 05986) investigated flowering
coffee. Copper sprays reduced the incidence of abnormalities and "crinkle leaf" in coffee. The
leaf rust. Monthly sprays were effective in abnormalities were rudimentary flowers, half-
increasing yield both of clean coffee and grade dried flowers and loss of flowering capability.
A coffee. The cause appeared to be low levels of
gibberllius in the developing bug, rudimentary
Kabara (16096) investigated yellow cherry and half-dried leaves and a very high level of
dieback of branches and poorly developed root gibberellins in the trees in case of loss of
system of 4-5 years old coffee plants. Soil flowers.
analysis indicated PH levels below the optimum
level for coffee. Magnesium exceeded calcium
levels, contrary to expected levels. Most of the Prabhakar (243487), Dickinson et. al. (23700,
severe cases affected trees in red soil, mainly 238127, 238719, 243799), Mburu et. al.
eroded humps and ridges. (17337), Maroko and Mwangi (04842), Maroko
(239488), Maroko (237149, 239936, 243930,
202314, 32453, 21538, 241677). Thuo and
Northmore (16100) investigated "pales" (i.e
Kamau (17992) and Wanjohi (12247) examined
yellowing buff colour) in roasted samples of
the face of contined application of copper in
coffee beans. The source of these pales
plants and soils associated with the cultivation
indicated that pales in the roast were derived
of coffee. High copper concentrations were
from trees which were growing under conditions
recorded in litter, bark, foliage and fruit. River
of nutritional stress, and the conditions were
water was found to have low copper content
aggravated by drought, resulting in loss of
and showed no significant pollution. For
leaves from trees. Trees affected gave the
potatoes, the peels had higher copper content
appearance of "overbearing" and cherries from
than any other tissue and did not affect potato
these trees were green-yellow, red-yellow, and
yields. Copper in the soil was found in greatest
did not get the normal fully red appearance and
concentrations in the surface upto 10cm depth.
ripening. These berries on further ripening
Concentrations of copper in the fruit was
became brown and graded "mbuni".
variable, being highest in the epicarb, but
concentrations in coffee beans were low.
Aduayi (15835) investigated nutritional effects
Njoroge (20586) studied the reponse of high
of copper. Higher levels of copper led to severe
density disease resistant coffee variety to the
internal chlorosis of leaves. High levels of
sizes of planting holes and rates of Farmyard
phosphorous depressed the toxic effects of
manure appplied there in on trees in two
high copper concentrations. Copper
densities . Increase of hole sizes and farmyard
concentrations in parts of the coffee plants
manure had no statistical significance but the
showed a linear relationship with increased
largest holes gave the best results while
levels of applied copper. Anon (1970) showed
Farmyard manure was optimal at 50 percent to
that cuprous oxide affected the composition of
Mn, Fe, and Cu in the leaves of the sprayed
2 CEREALS AND REGUMES
Michori (15436, 05962, 03086; 22104) showed
that application of boron caused a decrease of Pinkerton (05136) reported copper deficiencies
die-back (bacterial blight) in coffee. In plots widespread in Coast province and Rift Valley
where boron was applied at the rate of Province; zinc deficiency was widespread and
30g/tree/year, coffee trees showed less attack occurring in association with copper deficiency.
Molybdenum deficiency was recorded in Coast 3 PINEAPPLE
Pinkerton (17819, 17768, 02636) investigated
the major element deficiency symtpoms in
pineapple. Details of visual leaf deficiency
Anon (02423) investigated whether high water
symptoms were also described for nitrogen,
tables could cause symptoms of yellow wilt in
potassium, calcium, magnesium, sulphur,
sugarcane and found that it was not the cause.
boron, manganese, copper, zinc and
Wapakala (13137, 01320) investigated copper
deficiency in wheat, sorghum, barley, maize,
oats. He showed no significant difference in 4 SISAL
yield between the highest and intermediate
levels of both copper sulphate and phosphate in Pinkerton (01728, 9532, 12404, 17644, 12399,
wheat. In sorghum, oats and barley, the 244445) reported on symptoms on plants
deficiency, in addition to casing leaf chlorosis deprived of either of the following nutrients;
and necrosis, also resulted in delayed flowering nitrogen, phosphorous, potassium, calcium,
and empty ears. In Nandi setaria and kenya magnesium, sulphur, boron, manganese,
white clkers, the deficiency was characterized copper, zinc, molybdenum and iron.
by wilting and dropping leaf malformation
followed by wilting in Kenya white clover.
Mulamula (31885, 31810) investigated the
reponse of minor elements on wheat. There
were significant yield increase due to Ca and
Mg. 5 COTTON
Oduor (16637) showed that combined
application of the macronutrients as well as
Braun (231896) discussed side effects of inclusion of micronutrients significantly
fertilizer use development. keya and improved growth of cotton on soils from
Balasundaran (235833) reported on the Machakos and Embu Districts.
potential and constraints for inoculation of grain
legumes in Kenya (soybeans, kidney beans,
Rhizobium japonicum). Anyango (32244)
assessed the suitability of filtermud as a carrier
6 HORTICULTURAL TREE CROPS
for legume inoculants and found it a good
Anon (051169) investigated chlorosis of plums
Haque (247507) discussed copper in soils, and found no effect of application of fritled trace
plants and ruminant animal nutrition with elements. Robinson (00481) showed that
special emphasis to sub-Haran Africa. chlorosis/necrosis symptoms exhibited by the
older avocado leaves was due to magnesium
imbalance. Sheffield and Kulkarni (03882)
described abormal conditions and their cause
for elephant grass, molasses grass, pawpaw
and sisal. Kulkani and Sheffield (12383)
explained the stunting observed after grafting
the pawpaw trees. Adams et. al. (00809)
found that cashew seedlings necros was due to
deficiency of iron.