Weeks After Transplanting Research Articles

Preliminary studies on growth and fresh weight of lettuce (Lactuca sativa) as affected by clay pot irrigation and spacing.

An experiment (Completely Randomized Design) was set up to determine the effects of Clay Pot Sub-surface Irrigation (CPSI) and spacing on the growth and fresh weight of lettuce (Lactuca sativa). The treatments were: CPSI with spacing; 15 x 15 cm, 20 x 20 cm and 30 x 30 cm. Control treatments were Watering Can Irrigation (WCI) with the same spacing as above. Treatments were replicated three times given a total of 18 experimental units. Eighteen large enamel basins of 50/20 cm (diameter/height) were filled with good topsoil and a clay pot buried neck deep in each of the basins. Seedlings were planted in all the eighteen basins. Five Hundred mL of wastewater was applied daily to plants in each container having either clay pot or watering can treatment. Plant height increased from 2.50 to 4.25 cm within 6 Weeks after Transplanting (WAT) under CPSI and only increased from 2.14 to 2.99 cm under WCI. The CPSI also supported better leave growth and fresh weight. The fresh weight of lettuce increased almost two fold under 15 x 15 cm spacing compared to 20 x 20 and 30 x 30 cm.

Screenhouse Assessment of Reaction of Fluted Pumpkin, Telfairia Occidentalis Hook F. to Root-Knot Nematode Meloidogyne Incognita

Screenhouse studies were carried out between April – June and July – September, 2004 at the vegetable researchunit of National HorticulturalResearch Institute (NIHORT), Ibadan,Nigeria to investigate the reaction of five linesof Telfairia occidentalis (EN2000-4, EN2000-6, EN2000-10, EN2000-11, EN2000-13) to different populationlevels (0, 5000 and 10 000 eggs) of Meloidogyne incognita race 2. Seeds from five different matured pods ofTelfairia lines were planted on moist sawdust medium. They were watered every two days until germination andtransplanting. Experimental layout was a completely randomized design and each treatment was replicated fivetimes. Nematode inoculation was done at one week after transplanting. The plants were watered every two daysand observation of vine length, vine girth and number of leaves commenced two weeks after transplanting (WAT)on bi weekly basis and lasted till the 10th week. From the 4th WAT, roots were assessed for the presence of eggsevery five days in view of determining the generation time in the various lines. Soil nematode population and rootgall indices were determined at the end of the trial.Results showed that there were significant differences between the Telfairia lines in the measured parametersirrespective of the inoculum levels. EN2000-4 performed significantly better than the other lines. EN2000-13which closely followed EN2000-4 with respect to vegetative growth, recorded significantly higher galling indexthan all the other lines. There were significant differences between the inoculum levels. Inoculum levels wereinversely proportional to growth parameters and directly proportional to gall indices in all the lines. Chloroticpatches were also observed on the leaves of plants inoculated with 10 000 eggs. The uninoculated (control) plantsgave significantly better vegetative growth than their inoculated counterparts. The disparities in growth and yieldresponses indicate that there is genetic variability among the lines.

In-row Distances and Nitrogen Fertilization Programs for ‘Tasti-Lee’ Specialty Tomato

‘Tasti-Lee’™ (‘Fla. 8153’) is the first tomato (Solanum lycopersicum) released in Florida exclusively for the premium specialty market, with characteristic superior flavor and elevated lycopene concentration. Research was conducted to determine the appropriate nitrogen (N) fertilization and in-row distances for ‘Tasti-Lee’ tomato and thus improving the opportunities for successful adoption for this cultivar. Three N fertilization programs and two in-row distances were tested. Total N rates (204, 239, and 274 lb/acre) were the result of the combination of 50 lb/acre of N during prebedding plus each of the following drip-applied N fertilization programs: 1) 1.5 and 2.0 lb/acre per day from 1 to 4 weeks after transplanting (WAT) and 5 to 12 WAT, respectively; 2) 1.5, 2.0, and 2.5 lb/acre per day during 1 to 2 WAT, 3 to 4 WAT, and 5 to 12 WAT; and 3) 1.5, 2.5, and 3.0 lb/acre per day during 1 to 2 WAT, 3 to 4 WAT, and 5 to 12 WAT, respectively. In-row distances were 18 or 24 inches between plants, providing 5808 and 4356 plants/acre. Early and total marketable yields of ‘Tasti-Lee’ tomato were influenced by in-row distances and N fertilization programs, but not by their interaction. The highest early marketable fruit yield was found in plots treated with the highest N rate among fertilization programs (+6%), and in plots planted 18 inches apart (+7%) in comparison with the lowest N rate and the 24-inch spacing. Tomato plots treated with the highest N rate (274 lb/acre) resulted in the largest total marketable yield (+8%). Among the in-row distances, when plants were transplanted 18 inches apart, tomato total marketable yield increased by 18% compared with 24 inches between plants.

Effects of Transplanting Dates and Insecticide Frequency in the Control of Thrips tabaci Lindeman (Thysanoptera:Thripidae) on Onion (Allium cepa L.) in Sokoto, Nigeria

Two factors, transplanting date and insecticide frequency were combined to evaluate their effects in reducingpopulation of thrips and yield of onion. Transplanting was done at monthly interval from November throughMarch, while spraying was done fortnightly, starting from three weeks after transplanting (WAT) to nine WAT(3, 5, 7 and 9) using knapsack sprayer at 18.67g a.i./ha. Results showed that early transplanting done inNovember and December had fewer thrips than the subsequent ones. At 7 WAT, late transplanting made inFebruary had up to 191 thrips/plant and< 1 in the early transplants. First spray was effective in reducing thrips byabout 76% and second and subsequent sprays were less effective. There was significant difference betweentreatments (P

Effect of rainfall in the control of onion thrips, Thrips tabaci lindeman (Thysanoptera :Thripidae) in Sokoto, Nigeria

Field experiments were conducted in the dry seasons of 2001/2002 and 2002/2003 to study the major insect pests of onion using five dates of transplanting and five insecticidal spray regimes of λ-cyhalothrin in a randomised complete block design, replicated three times. Results indicate that thrips were the major insect pests of onion, which started colonizing onion plant in December, but the number was low until the third week of January and peaked in mid-March with up to 600 thrips/plant. In the course of the research, rainfall was recorded on 12 April, 2002 and 6 April, 2003 and this was observed to exert greater control of thrips than either planting date or the chemical (78%). In 2001/2002 season, there was a reduction in thrips population from 86-9 thrips/plant (89%) in zero spray in March transplant from 5-6 weeks after transplanting (WAT) before rising to 25 at 8 WAT, in February transplant the reduction was from 78-13 thrips/plant in zero spray. In 2002/2003 season only a slight increase in number of thrips/plant (12-15) was observed from 4-5 WAT in March transplant, but in February transplant not affected by rain there was increase was from 21-89. Where rainfall can be simulated, a greater control can be achieved, where thrips are washed away by the force of the rain, unlike chemical that may not reach the innermost leaves.

Effect of a complementary application of Algifol nutrient solution and npk on growth, flowering and yield of tomato in a northern guinea savanna soil of Nigeria

The effect of a complementary application of Algifol nutrient solution (Alg) and inorganic NPK fertilizers on growth, flowering and yield of tomato was investigated in 1999 and 2000 at Samaru, Kaduna State of Nigeria. Four levels of the nutrient solution were applied as (2, 1, 12 and 2Alg) at the rates of 5, 10, 15 and 20ml per 100ml of water while the NPK levels were applied as (3, 2, : and 1 or Full NPK) at the rate of 125:50:50kgha-1, N, P2O5 and K2O respectively. The combined Algifol and NPK levels were 2Alg + Full Alg, 1Alg+1/4 NPK, 1Alg+1/2 NPK, 1Alg + : NPK, 1Alg + Full NPK, 12 Alg + 2 NPK and 2Alg + 3 NPK at the same rates for the Algifol and NPK and one control. Parameters measured were plant height, number of leaves, number of flowers, fresh fruit yield and dry fruit yield per plant. The results obtained showed that the fertilizer treatment effect on plant height was not significant at 6 and 12 weeks after transplant (WAT) in 1999 but in 2000, the treatment effect was highly significant (P=0.01). Foliage production in 1999 and 2000 was not significant at 6WAT but highly significant at 12WAT indicating a positive influence of the treatments at the time of growth maturity relative to the initial growth period of the crop. Also, the treatment effects on flowering and dry fruit yield per plant were highly significant (P=0.01) in the two years of study whereas in the fresh fruit yield, the effect was significant (P=0.05) in 1999 and highly significant in the second trial in 2000. Number of flowers per plant was positively and highly significantly correlated (r=0.75**; 0.86**) with fresh fruits and dry fruits yields respectively. Treatments having both Algifol nutrient solution and inorganic NPK combinations recorded the best flowering and fruit yield in relation to the single doses of Algifol or NPK.KEYWORDS: Nutrient solution, savanna soil, combined application, Alfisol

Weed management in onion using chemical, non-chemical, and manual methods

SummaryWeed management studies in onions grown from seedlings were conducted during 2006 and 2007 at the National Agricultural Research Centre, Islamabad, Pakistan. Applications of pendimethalin at 0.825 l a.i. ha–1, or oxadiazon at 0.240 l a.i. ha–1, 2 d after transplanting (DAT) seedlings were evaluated alone, and in combination with one manual weeding, for their effects on weed competition and bulb yields. Other weed control treatments included the application of rice straw mulch 2 weeks after transplanting (WAT) combined with one manual weeding at 9 WAT, or a newspaper and rice straw mulch applied 2 WAT. Compared to the weed-free situation, competition with weeds caused reductions in bulb yields of 62% and 68% during the first and second year, respectively. Polygonum plebejum, Amaranthus viridis, Cyperus rotundus, and Coronopus didymus were the dominant weeds recorded in the field. Mulching reduced weeds by 56 – 60% compared to the chemical weed treatments. Compared to the weed-free treatment (four manual weedings at monthly intervals), which is a traditional method to control weeds in onion, bulb yields increased significantly under the rice straw mulch or when treated with pendimethalin in combination with one manual weeding at 9 WAT. The latter two treatments, on average, resulted in the highest increases of 26 t ha–1 and 24 t ha–1 in bulb yields with net returns of US$ 1,522 ha–1 and US$ 1,486 ha–1, respectively over the non-treated control.

Response of Onion(Allium cepa L.) to Nutrient Sources and Weeding Regimes in Sudan Savannah

Onion is an important vegetable in Nigeria, but its production and quality are often low due to inappropriate agronomic practices like good nutrient sources and proper weed control. A study was carried out for two years to investigate the response of onion ( Allium cepa L.) to nutrient sources and weeding regimes on the bulb quality during 2006/2007 and 2007/2008 seasons at Sabke Dam, Katsina State (12o56’ N;7 o45’E). The experiment consisted of five sources of nutrients(mineral fertilizer, poultry droppings, rumen content, farm yard manure and no fertilizer as control) and four hoe weeding regimes at 3, 6, 9 weeks after transplanting(WAT) and weedy check as control. The treatments were arranged in a randomized complete block design with three replications. Results indicated that poultry droppings significantly produced higher proportion of marketable bulbs, soluble solids and dry matter as well as high cured bulb weight and bulb yield compared to other nutrient sources in both years. The control recorded the least in respect of all quality characters studied. Weeding regimes significantly (P weight in 2007/2008. Good quality marketable bulbs of onion was best obtained from poultry droppings in combination with weeding at 6 WAT

Environmental conditions affect pectin solubilization in cherry tomato fruits grown in two experimental Mediterranean greenhouses

Considering the economic importance of the tomato and its nutritional benefits for human health, we studied how different environmental factors [temperature, solar radiation and vapour–pressure deficit (VPD)] influenced the pectin solubilization and the calcium concentration in cherry tomato fruits ( Solanum lycopersicum cv. Naomi) grown in two experimental greenhouses: improved parral type (low-technology) and multispan type (high-technology). For three years (2004, 2005 and 2006), three fruit samples were taken over the entire production period: at the beginning of harvest [16 weeks after transplanting (WAT)], at mid-harvest (26 WAT), and at the end of harvest (35 WAT). Values for temperature, solar radiation, and VPD peaked in the third sampling in both greenhouses during the three years, being higher in the parral greenhouse during the production cycle. No-market production and peroxidation indicators [measured as H 2O 2 and malondialdehyde (MDA) concentrations] significantly increased at the end of the productive period in both greenhouses, indicating the presence of oxidative stress caused by the rise in temperature, solar radiation, and VPD, which was more pronounced in the parral greenhouse. Water-soluble pectins, pectate, and protopectin contents were measured, revealing an increase in the former two and a reduction in the latter under environmental stress. This indicates a clear pectin solubilization in cherry tomato fruit. The enzymes pectolytic polyglacturonase (PG), pectin methylesterase (PME), and pectate lyase (PEL), altered their activities during the third sampling, while the calcium concentration fell drastically. Therefore, both the increase in pectin solubilization as well as the reduction in the Ca concentration during harshest environmental stress in the third sampling, especially in the parral greenhouse, could degenerate the textural properties of the cherry tomato, reducing its quality and consumer acceptance.

Effects of staggered planting dates on the control of Thrips tabaci Lindeman and yield of onion in Nigeria

Eight–week old onion seedlings were transplanted from December to April in 2001-2002 and November to March in 2002-2003 growing seasons to assess the level of thrips damage and its effect on onion bulb yield. Results obtained revealed that thrips started appearing from January but the number was very low until end of February when the population reached 12 thrips/plant. November transplant was free of thrips up to 9 weeks after transplanting (WAT), December transplant up to 8 WAT, January transplant up to 6 WAT, while February, March and April transplant had population of >5 thrips /plant at 4 WAT. There was a significant difference (P< 0.05) between plantings from 4-14 WAT. The peak of thrips incidence in the various transplants were as follows: November at 15 WAT (120), December at 12.5 WAT (234), January at 9.5 WAT (373), February at 8.5 WAT (217), March at 6 WAT (41.2) and April at 5 WAT (20). Onion bulb yields were also found to differ in descending order as follows: November (48 t/ha), December (42 t/ha), January (13.5 t/ha), February (5.5 t/ha) and March (1.5 t/ha). Key words: Onion, Thrips tabaci, weeks after transplanting.

Critical Period of Weed Interference in Rainfed and Irrigated Tomatoes in Nigerian Savanna

Field trials were conducted to assess the critical period of weed interference in tomato on the farm of the Institute of Agricultural Research, Samaru (11011\'N, 07038\'E) in the Northern Guinea Savannah ecological zone of Nigeria in 1989 and 1990 wet seasons and at the Irrigation Research Station of the Institute of Agricultural Research, Kadawa (110N39\'N,08002\'E) in the Sudan Savanna ecological zone of Nigeria in 1987/88 and 1988/89 dry seasons. Each trial consisted of two sets of treatments. One set of treatments consisted of plots initially kept weed-free for 3, 6, 9 and 12 weeks after transplanting by weeding and with hand hoes and subsequently kept unweeded until harvest. The other set of treatments consisted of plots initially kept weed infested for corresponding periods and subsequently kept weed-free until harvest. Two treatments of weed infestation and weed-free throughout the crop growth were also included in checks. In all the trials, weed interference beyond 6 weeks after transplanting (WAT) significantly depressed various crop growth parameters in the tomato fruit yield compared with the crop kept weed-free through out its life cycle. The crop was most critically affected by weed interference between 3 and 6 WAT.In order to obtain tomato fruit yield comparable to that of weed-free check, it was required to keep the crop weed-free for 6weeks after transplanting and beyond. Weed infestation throughout the crop life cycle resulted in about 40 to 60% reduction in potential tomato fruit yield compared with the appropriate maximum obtained in trials. JARD Vol. 2 2003: pp. 32-41

Combinations of Nitrogen Rates and Irrigation Programs for Tomato Production in Spodosols

Two field studies were conducted to compare the effects of preplant nitrogen (N) rates and irrigation programs on tomato (Solanum lycopersicum) growth and yields. Irrigation programs were seepage (subsurface) irrigation alone at a water volume of 28 acre-inches/acre per season and seepage plus drip irrigation at a volume of 28 and 14 acre-inches/acre per season, respectively. Preplant N fertilization rates were 200, 250, and 300 lb/acre, using ammonium nitrate as the N source. There were significant irrigation program by N rate interactions for nitrate (NO3−) petiole concentrations at 8 weeks after transplanting (WAT), and yield of extra-large fruit and total marketable fruit, but not for plant height at 5 and 7 WAT. The highest NO3-N petiole concentrations were found in plots treated with 200, 250, and 300 lb/acre for N and seepage plus drip irrigation, and with 300 lb/acre N under seepage irrigation alone. For the total marketable fruit weight, there were no differences among N rates in those plots irrigated with the seepage plus drip combination, ranging between 23.8 and 25.9 tons/acre. However, there was a significant N effect in plots receiving only seepage irrigation with marketable fruit weight almost doubling from 12.0 to 22.7 tons/acre when applying 200 and 300 lb/acre N, respectively. Both irrigation programs had equivalent performance when 300 lb/acre N were applied.

Combinations of Nitrogen Rates and Irrigation Programs for Tomato Production in Spodosols

Two field studies were conducted to compare the effects of preplant nitrogen (N) rates and irrigation programs on tomato (Solanum lycopersicum) growth and yields. Irrigation programs were seepage (subsurface) irrigation alone at a water volume of 28 acre-inches/acre per season and seepage plus drip irrigation at a volume of 28 and 14 acre-inches/acre per season, respectively. Preplant N fertilization rates were 200, 250, and 300 lb/acre, using ammonium nitrate as the N source. There were significant irrigation program by N rate interactions for nitrate (NO3−) petiole concentrations at 8 weeks after transplanting (WAT), and yield of extra-large fruit and total marketable fruit, but not for plant height at 5 and 7 WAT. The highest NO3-N petiole concentrations were found in plots treated with 200, 250, and 300 lb/acre for N and seepage plus drip irrigation, and with 300 lb/acre N under seepage irrigation alone. For the total marketable fruit weight, there were no differences among N rates in those plots irrigated with the seepage plus drip combination, ranging between 23.8 and 25.9 tons/acre. However, there was a significant N effect in plots receiving only seepage irrigation with marketable fruit weight almost doubling from 12.0 to 22.7 tons/acre when applying 200 and 300 lb/acre N, respectively. Both irrigation programs had equivalent performance when 300 lb/acre N were applied.

배추에 대한 배추흰나비(Artogeia rapae L.)의 요방제수준

배추에서 배추흰나비의 요방제수준을 설정하기 위해 온실 및 포장에서 실험을 수행하였다. 예비실험으로서 배추흰나비 2령충을 다섯 밀도 수준 접종하고 피해정도를 조사하였다. 배추 포기당 유충 1마리 접종에 의한 잎피해면적은 정식3주차 배추에서 섭식 1주일후 657.7 <TEX>$mm^2$</TEX>, 정식 6주차 배추에서 섭식 2주일후 2495.8 <TEX>$mm^2$</TEX>로 나타났다. 포장실험에서는 배추흰나비 유충 1-7마리를 시험구(배추 20주)에 접종하였다. 3주간 섭식후, 접종 유충 밀도(X)에 따른 수량감소율(Y)은 다음 두가지 식, 즉 정식 3주차 배추는 Y=1.7640X-0.3049 (<TEX>$R^2$</TEX>=0.9901), 정식 6주차 배추는 Y=1.0305X-0.2976 (<TEX>$R^2$</TEX>=0.9398)로 각각 추정되었다. 접종한 유충밀도와 배추 피해지수간의 상관성을 바탕으로, 수량 감소율(gain threshold, 수익역치) 5%로 전제한 배추흰나비 2령 유충의 요방제수준은 정식 3주차 배추에서 20주당 3.0마리, 정식 6주차 배추에서 20주당 5.1마리로 추정되었다. This study was conducted to estimate the control thresholds (CTs) of imported cabbage worm, Artogeia rapae L., injuring Chinese cabbage. The second instar larvae of A. rapae were inoculated with five density levels on each Chinese cabbages transplanted three weeks earlier under greenhouse condition, and checked injury rates after allowing their feeding for one week and two weeks, respectively. The average leaf area consumed by single larvae was 657.7 <TEX>$mm^2$</TEX> in plots inoculated at three weeks after transplanting (WAT) and 2495.8 <TEX>$mm^2$</TEX> in plots at 6-WAT, respectively. In the field experiment, different numbers of A. rapae ranged from one to seven larvae were inoculated on 20 plants. The percent yield reduction (Y) of Chinese cabbage infested by different densities of A. rapae (X) for a three-week period was estimated by the following equation; (1) Y=1.764X-0.3049 (<TEX>$R^2$</TEX>=0.9901) in plots inoculated at 3-WAT; and (2) Y=1.0305X-0.2976 (<TEX>$R^2$</TEX>=0.9398) in plots inoculated at 6-WAT. Based on the relationships between the densities of A. rapae larvae and the yield index of Chinese cabbage, the number of second instar larvae which caused 5% loss of yield (gain threshold proposed by Japan), was estimated as 3.0 per 20 plants for the 3-WAT and 5.1 for the 6-WAT.

Comparative Study of the Effect of Different Weed Management Strategies on Disease Severity and Marketable Yield of Paprika (Capsicum Annuum L.) in the Smallholder Farming Sector of Zimbabwe

Comparative Study of the Effect of Different Weed Management Strategies on Disease Severity and Marketable Yield of Paprika (Capsicum AnnuumL.) in the Smallholder Farming Sector of ZimbabweOn-farm trials were conducted in the Chinyika Resettlement Area of Zimbabwe under dryland conditions to investigate the effects of different weed management methods on disease incidence, severity and paprika (Capsicum annuum) pod yield. The weed control treatments included hand weeding at 2 and 6 weeks after transplanting (WAT); ridge re-moulding at 3,6 and 9 WAT; application 4l/ha Lasso (alachlor) immediately after transplanting, and Ronstar (oxidiazinon) at 2l/ha tank mixed with Lasso at 2l/ha one day before transplanting. The herbicide-water solution was applied at the rate of 200l/ha using a knapsack sprayer. Major diseases identified were bacterial leaf spot (Xanthomonas campestrispv.vesicatoria), cercospora leaf spot (Cercospora unamunoi), grey leaf spot (Stemphylium solani) and powdery mildew (Leveillula taurica) in both seasons. For the 2000/2001 season hand weeding at 2 and 6 WAT and ridge re-moulding at 3, 6 and 9 WAT had the greatest reduction effect on the area under disease progress curve (AUDPC) and the highest marketable fruit yield. In the 2001/2002 season, both herbicide treatments had the same effect as hand weeding and ridge re-moulding on AUDPC and marketable fruit yield. The least weed density was obtained by ridge re-moulding at 3, 6, and 9 WAT in the 2000/2001 season. Weed density was statistically the same across all treatments except the check treatment in 2001/2002 season. Hand weeding operations were significantly (p &lt; 0.05) effective and consequently gave the highest added profits mainly because of their effect on major weeds such asDatura stramonium.

EFFECTS OF STAND LOSS, PLANTING DATE, AND REPLANTING METHOD ON YIELD AND QUALITY OF FLUE-CURED TOBACCO

Abstract Research was conducted at one location in 2003 and two locations in 2004 and 2005 to evaluate the effects of stand loss, planting date, and replanting method on flue-cured tobacco yield and quality. Stand loss treatments included a 10%, 20%, 30%, and 40% stand loss at two and four weeks after transplanting (WAT). In recent years, early season infections by Tomato spotted wilt virus (TSWV) have caused significant stand losses in North Carolina, so an additional treatment was included to simulate the effects of plant loss to tomato spotted wilt. Simulated losses consisted of a 10%, 10%, and 20% stand loss at 3, 4, and 5 weeks after transplanting, respectively. Planting date treatments included planting at the normal transplanting date and at 2, 3, 4, and 5 weeks after the normal transplanting date. To evaluate the effects of replanting method, tobacco was replanted at 2 or 4 weeks after normal replanting on an existing row ridge, a rebedded row ridge, and a tilled and rebedded row ridge. Due to exc...

Control of Thrips tabacci Linderman (Thysanoptera: Thripldae) on Onion (Allium cepa Linn.) in Sokoto, Nigeria

Five onion, transplants were sprayed with A.-cyhalothrin (Karate 2.5EC) at 18.67g a. i. Iha (747mllha) from Jan.-May in 2002 and Dec.-May in 2003. Spraying was spaced at fortnightly intervals starting at 3 weeks after transplanting (WAT). Results indicated that unsprayed plots significantly differed (P&lt; 0.05) from the sprayed plots in thrips population at 4, 6, 8 and 10 WAT. Two sprays significantly increased onion bulb yield by 39% in 2001/2002 whist three sprays increased it by 26% in 2002/2003.

Suppression of Digitaria sanguinalis and Amaranthus palmeri using autumn‐sown glucosinolate‐producing cover crops in organically grown bell pepper

SummaryExperiments were conducted to compare growth characteristics, biomass production and glucosinolate content of seven autumn‐planted glucosinolate‐producing cover crops that were terminated the following spring. The control of Digitaria sanguinalis and Amaranthus palmeri following cover crop incorporation into soil was characterised and fruit yields of bell pepper transplanted into cover crop‐amended soil were determined. Differences in glucosinolate concentration and composition were noted between cover crop roots and shoots and among cover crops. Total biomass production by cover crops ranged from 103 g m−2 for garden cress to 894 g m−2 for Indian mustard (F‐E75), but cover crop biomass was not correlated with D. sanguinalis and A. palmeri control. D. sanguinalis and A. palmeri control in bell pepper varied by cover crop. D. sanguinalis control by cover crops ranged from 38% to 79%, and A. palmeri control was 23% to 48% at 4 weeks after transplanting (WATP) bell pepper in 2004. D. sanguinalis control was positively correlated with total glucosinolate production, but A. palmeri control was not. D. sanguinalis control in 2005 ranged from 0% to 38% at 2 WATP. In the absence of weeds, cover crops did not negatively affect fruit yields which were often higher than in the absence of a cover crop. Glucosinolate‐producing cover crops are not a stand‐alone weed management strategy, but some will provide early season control of D. sanguinalis and A. palmeri without having a negative effect on transplanted bell pepper.

Response of tomato to NPK fertilizer and foliar application of algifol nutrient solution in a Nigerian Savanna soil

Responses of tomato (Lycopersicum esculentum Mill) to both foliarly applied Algifol (Alg) and soil applied inorganic NPK fertilizers were investigated between July - November, 1999 and January - May, 2000 in a greenhouse at Samaru, Institute of Agricultural Research Experimental Station, Ahmadu Bello University, Zaria. Four Algifol levels (½, 1, 1½ and 2) were applied at the rates of 5:10:15:20ml per 100ml of water. The inorganic fertilizer levels consisted of ¼, ½, ¾ and 1 or Full NPK applied at the recommended rate of (125:50:50kgha-1, N, P2O5 and K2O). Seven Alg and NPK combination ratios were as follows: ½Alg + Full NPK, 1Alg+1/4 NPK, 1Alg+1/2 NPK, 1Alg + ¾ NPK, 1Alg + Full NPK, 1½ Alg + ½ NPK and 2Alg + ¼ NPK and were applied at the same rate for Algifol and NPK as above. Data were collected on plant height, number of leaves and number of fruits per plant. The results obtained revealed that plant height per plant was not significantly different (P>0.05) against treatments at 8 and 12 weeks after transplanting (WAT) in 1999, but in 2000, the treatments effect was significant (P

Effects of Yellow and Purple Nutsedge Time of Establishment on Their Distance of Influence on Bell Pepper

Field trials were conducted to determine the effect of yellow nutsedge (Cyperus esculentus) and purple nutsedge (C. rotundus) time of establishment on their distance of influence on bell pepper (Capsicum annuum). A single seedling of each weed species was transplanted 1, 2, 3, 4, and 5 weeks after transplanting (WAT) bell pepper. Each weed was separately established in the center of plots within double rows of bell peppers. Crop height and yield were determined from bell pepper plants located at 6, 13.4, 24.7, and 36.5 inches away from each weed. Bell pepper height was unaffected by weed species, time of establishment, or the interaction between these factors. Marketable yield data indicate that yellow nutsedge was more aggressive than purple nutsedge interfering with bell pepper. When yellow nutsedge was established at 1 WAT, bell pepper yield reduction was between 57% and 32% for plants at 6 and 13.4 inches away from the weed respectively, which represents a density of ≈0.14 plant/ft2. One purple nutsedge plant growing since 1 WAT at 6 inches along the row from two bell pepper plants (0.43 plant/ft2) produced a yield reduction of 31%. These results indicate that low nutsedge densities, which are commonly believed to be unimportant, can cause significant bell pepper yield reductions.