Aims: In spinach, transplanting has replaced direct seeding but small containers may cause root restriction effects that would be decreased post-transplant yield. Although a single hormonal regulator (BAP) spray is effective in overcoming root restriction, the mechanisms involved are unknown. The aim of this work was to analyze spinach growth changes by the use of different plug cell volumes and BAP as foliar spray.
Study Design: A randomized complete block factorial design with three blocks was used.
Place and Duration of Study: The experiments were conducted at the INTA Balcarce Experimental Station campus, Argentina (37º 45′ S, 58° 18′ W and altitude 130 m) from 5th March to 24th May 2008 and repeated once from 15th March to 19th May 2009.
Methodology: We analyzed growth changes by the use of different plug cell volumes and BAP as foliar spray on dry weight accumulation and partitioning in Spinacea oleracea plants in two field experiments.
Results: The use of large plug cell volumes and BAP sprays at the pre-transplant stage increased plant growth, through an increase in the relative growth rate (RGR) and the rate of leaf area expansion (RLAE). We found a close direct relationship between RGR and net assimilation rate (NAR) but an inverse relationship between RGR and leaf area ratio (LAR). In addition, we found that NAR significantly increased as leaf thickness, intercellular spaces and stomatal density increased. A change in dry weight partitioning toward shoots was found as well.
Conclusion: From a grower’s point of view, the use of large plug cell volume would increase spinach growth. On the other hand, a promising approach to increasing crop productivity is the use of plant growth and development regulators such as BAP.
Farming systems in cocoa over the last three decades have involved the use of new hybrid plant varieties, which produce pods throughout the year, intensified fertilizer use, and misguided pesticide applications by some farmers. Resource availability in terms of abundance of feeding and breeding sites and ecological disruption as a consequence of climate change and bad agronomic practices have increased the importance of insect pests on cocoa. Historically the major management tool for hemipteran pests has been calendar spraying with conventional insecticides. Considerable progress was made at the turn of the last century by replacing organochlorine insecticides for cocoa mirid control. But inappropriate timing and inefficient application is probably reducing the viability of otherwise acceptable products in some areas. Integrated Pest Management (IPM) strategy for mirids and other insect control should involve great investment in pest surveillance, and be based primarily on the use of cultural practices of removal of excess chupons, shade management and host variety resistance. These practices must primarily aim at minimising mirid-associated dieback disease and stink bug deformation of pods, and should be supplemented in some cases by the use of insecticides (up to two applications in February to May at 28-days intervals) depending on the pest populations, damage levels as well as intensity of activity of pollinating insects, with additional two applications during September to December when pest problems may arise. Improved methods of monitoring and prediction should assist in early identification of specific problems in different farms. The rotational use of different active ingredients should also take into account factors such as application methods, compatibility and correct timing. Careful planning is necessary to formulate a flexible control system.
Aims: This experiment aimed to determine whether the soil application of organic fertilizers can help the establishment of cacao and whether shade alters its response to fertilizers. Study Design: The 1.6 ha experiment was conducted over a period of one crop year (between April 2007 and March 2008) at the Cocoa Research Institute of Ghana. It involved four cacao genotypes (T 79/501, PA 150, P 30 [POS] and SCA 6), three shade levels (‘light’, ‘medium’ and ‘heavy’) and two fertilizer treatments (‘no fertilizer’, and ‘140 kg/ha of cacao pod husk ash (CPHA) plus poultry manure at 1,800 kg/ha). The experiment was designed as a split-plot with the cacao genotypes as the main plot factor and shade x fertilizer combinations as the sub-plots. Methodology: Gliricidia sepium and plantains (Musa sapientum) were planted in different arrangements to create the three temporary shade regimes for the cacao. Data were collected on temperature and relative humidity of the shade environments, initial soil nutrients, soil moisture, leaf N, P and K+ contents, survival, photo synthesis and growth of test plants. Results: The genotypes P 30 [POS] and SCA 6 showed lower stomatal conductance under non-limiting conditions. In the rainy seasons, plants under light shade had the highest CO2 assimilation rates. However, in the dry season, plants under increased shade recorded greater photosynthetic rates (P = .03). A significant shade x fertilizer interaction (P = .001) on photosynthesis in the dry season showed that heavier shade increases the benefits that young cacao gets from fertilizer application in that season. Conversely, shade should be reduced during the wet seasons to minimize light limitation to assimilation. Conclusion: Under ideal weather conditions young cacao exhibits genetic variability on stomatal conductance. Also, to optimize plant response to fertilizer application shade must be adjusted taking the prevailing weather condition into account.
Three years field studies were conducted at teaching and research farm of faculty of Agriculture, Bayero University Kano to evaluate the effect of various tillage practices on weed control and yield of groundnut. The study consisted of nine (9) treatments comprising of two (2) zero tilled, three (3) minimum and four (4) conventional tillage practices arranged in randomized complete block design with three (3) replications. Identification of weeds was made to species level and data were collected on weed count, cover score and weed dry weight. At maturity, groundnut stand and kernel yield were assessed. Data were analyzed using SAS (version 9.3). The result showed a higher weed infestation in T1, T2, T3, T4 and T6 (control) than in T9, T8 and T7 tillage practices from all the three years of study. Perennial weeds species were more frequent in T1 and T2 tilled plots than in T9 and T8 tilled plots. T9 had the least cover score while T6 (control) had the highest weed cover score in all the trials. In all the trials, T1 consistently recorded the highest weed dry matter while T9 recorded the lowest. The highest stands of 35333 ha-1 and 37852 ha-1 were observed at T9 in 2008 and 2010 trials respectively while control (T6) was among the least. The highest and lowest stands of 41556 and 17778 ha-1 were observed at T8 and T5 respectively in 2009 trial. Generally T9 had the highest kernel yield of 1067.7 kg ha-1 in 2008 and 1151 kg ha-1 in 2010 season. Tillage practices modified weed floral composition of the study area. T9 and T8 reduced the level of weed occurrences and resulted in better weed control with higher kernel yield than T1, T2, T3, T4, and T6 tillage practices. T8 and T9 tillage practices are recommended for weed control in the study area.
Assessment of genetic variability of the crop varieties is essential to assure selection of genetically divergent lines useful for the future breeding programmes. Thus, genetic diversity assessment of 24 elite Indian rice varieties was performed based on 24 agro-morphological traits and 86 SSR markers. The morphological and grain traits exhibiting significant variation are useful for discrimination of the rice varieties and were confirmed by Principal Component Analysis. Genetic diversity assessment based on SSR markers displayed genetic similarity coefficients and grouped the varieties into five major clusters. The genetic population structure obtained was predominantly associated with UPGMA clustering and the structure bar plot. Cluster analysis based on both phenotype and SSR marker data did not show perfect congruence between the two measures of genetic diversity. However, the correlation between morphological and molecular diversity was positive and significant (r = 0.36 P<10-4) indicating usefulness in classification of rice varieties.
Aims: To evaluate the effects of various treatment combinations of water contaminated with faecal sludge on the growth and microbiological characteristics of lettuce (Lactuca sativa L.) cultivated around the river Avo'o discharged zone.
Study Design: We used randomized plots in which young lettuce plants obtained from a nursery were planted in four sites (S0, S1, S2 and S3) situated 3000, 810, 100 and 350 m from the raw discharge area along river Avo'o.
Place and Duration: Field studies were carried out in Nomayos (Yaounde) during the 2009-2010 growing seasons while laboratory analysis were effected at the waste water research unit of the Department of Plant Biology at the University of Yaounde I.
Methodology: Faecal streptococci, faecal coliforms and parasitic characteristics were determined in raw discharged sludge from river Avo’o water samples collected at three different points (P1, P2, P3) and in lettuce using standard protocols. Growth parameters of the lettuce plants were also evaluated.
Results: Faecal sludge, water from river Avo'o and L. sativa showed high levels of bacteriological and parasitological pollutants. The results also revealed high concentrations of faecal coliforms and faecal streptococci (6092 and 3390 CFU/100 ml respectively), and helminth eggs (> 273 eggs / L) in water. Treatment 3 (S3) showed the largest number of leaves
Nine male grower West African Dwarf (WAD) goats with an average weight of 9.30 kg, aged between 5-7 months were used in a completely randomized design to assess the growth performance and blood profile of WAD goats fed shea butter (Vitellaria paradoxa) leaves and supplemented with concentrate diets containing different levels of sweet orange (Citrus sinensis) peel meal (SOPM). Three dietary treatments were formulated and compounded to contain 0%, 25%, and 50% SOPM, and were designated T1, T2, and T3 respectively in an eighty-four day feeding trial. Results showed that mean daily weight gain (18.10-27.14 g/day), mean daily feed intake (426.6-462.0 gday/) and final weight (10.20-10.39 kg) were not significantly different (P>0.05) among the treatments. Packed cell volume (PCV), red blood cells (RBC), haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC) and serum biochemical components showed no significant change among the treatments (P>0.05). This showed that WAD goats fed Shea butter as forage can be supplemented with diets containing up to 50% SOPM without compromising either the growth performance or the health status of the animals.