A. Z. Khan

Immunomodulatory and hepatoprotective role of feed‐added Berberis lycium in broiler chicks

BACKGROUND A large number of plants and their isolates have been shown to potentiate immunity. Some plants exert anti-inflammatory and anti-stress effects, others hepatoprotective activity. In this study, 320 1-day-old broiler chicks were randomly divided into four major groups A, B, C and D and fed rations supplemented with 0, 15, 20 and 22.5 g Berberis lycium kg⁻¹ ration respectively. Each group was further divided into two subgroups, one vaccinated against Newcastle disease (ND) and infectious bursal disease (IBD), the other non-vaccinated. Antibody titre against IBD and ND, relative weight of lymphoid organs, post-challenge morbidity and mortality, serum hepatic enzymes and total serum protein were observed. RESULTS Group C had higher anti-IBD and anti-ND antibody titres. Relative bursa weight in groups C and D was higher until day 28, but birds in group C performed better at later stages of examination. Relative spleen weight was highest in group C. During initial stages there was no effect on relative thymus weight, but at later stages the effect was significant. Groups C and D performed similarly in terms of relative thymus weight. The birds were challenged to field IBD through intramuscular injection at a dose rate of 0.5 mL per bird. Post-challenge morbidity was lowest in groups C and D, while treatment significantly (P < 0.001) affected mortality amongst affected (morbid) birds. Levels of serum alanine aminotransferase and alkaline phosphatase were lowest in group C. Serum protein was similar in all groups and in both vaccinated and non-vaccinated broiler chicks. CONCLUSION Berberis lycium added to feed at 20 g kg⁻¹ is effective in improving immunity against ND and IBD as well as liver function in broiler chicks.

Plant density and nitrogen effects on growth dynamics, light interception and yield of maize

Maize (Zea mays L.) growth and yield are most sensitive to variations in plant density and nitrogen (N) in north-western Pakistan. This study was conducted on the Agricultural Research Farm of NWFP (North West Frontier Province) Agricultural University, Peshawar, from 2002–2004 to establish an accurate plant density and N management system aimed at high yield of maize. The 2 × 3 × 6 factorial experiment was designed having two plant densities (P1 = 60,000 and P2 = 100,000 plants ha−1) and three nitrogen rates (N1 = 60, N2 = 120 and N3 = 180 kg N ha−1) applied to the main plots, while six split application for N in different proportions were applied to subplots at different growth stages of maize in two equal (S1), three equal (S2), three unequal (S3), four equal (S4), five equal (S5) and five unequal splits (S6) at sowing and with 1st, 2nd, 3rd and 4th irrigation at two-week intervals. Growth rate and yield increased with elevated dose and number of N split applications. Improved endurance to high stands allowed maize to intercept and use solar radiation more efficiently, contributing to the remarkable increase in the crop growth rate and yield.

Soil amendments and seed priming influence nutrients uptake, soil properties, yield and yield components of wheat (Triticum aestivum L.) in alkali soils

The effects of soil amendments [i.e., control, gypsum, farmyard manure (FYM), and gypsum + FYM] and seed priming (i.e., unprimed, seed soaked in water for 10 hr prior to sowing, and seed soaked in 0.4% gypsum solution for 10 hr prior to sowing) were assessed on growth and yield of wheat (Triticum aestivum L.) crop in alkali soil in northwestern Pakistan. A split plot design was used, keeping priming methods in main plots and soil amendments in sub-plots. The results showed that the effects of soil amendments and seed priming on grain yield, straw yield, harvest index and number of spikes were significant but their interactive effect was non-significant. The highest crop yields and yield index were obtained with gypsum + FYM amendments, and seed priming with gypsum solution. The effect on seed emergence, plant height and number of grains per spike was, however, not significant. Grain yield increased by 104% in gypsum + FYM treatment over control and by 16.8% with seed primed in water, followed by 8.5% with priming in gypsum solution, as compared to non-priming. The weight of 1000 grains was significantly increased by 35% in gypsum + FYM treatment and by 15.8% in gypsum priming. The phosphorus (P) and potassium (K) content increased with soil amendments. Soil pH and gypsum requirement reduced significantly with soil amendments. The blend of gypsum and FYM has improved the properties of salt-affected soil and enhanced fertility for optimum production of wheat in addition to the beneficial effect of seed priming in gypsum solution on crop yield. Using these amendments could be ameliorative in removing the adverse effect of the salt-affected soils, rendering the soil a good medium for plant growth.

Comparing Application Methods for Boron Fertilizer on the Yield and Quality of Tobacco (Nicotiana tabacum L.)

The present study is based on the hypothesis that different methods of supplying boron (B) may have different effects on the yield and quality performance of tobacco crop. A field experiment was conducted to study the effect of different methods of B fertilization on the yield, quality, and leaf composition of flue-cured Virginia tobacco (cv. K-399) in 2007 at the Pakistan Tobacco Research Station, Mansehra. Three different methods (i.e., foliar spray, soil application, and root dipping at the rates of 0.25 kg ha–1, 1 kg ha–1, and 0.5 mg B L–1, respectively) in the form of boric acid along with a control (where no B was applied) were used in a randomized complete block design and replicated four times. Results revealed that different methods of B application significantly affected tobacco yield, quality, and nutrient uptake compared to the control. Maximum leaf area of 707 cm2, green leaf yield of 18553 kg ha–1, cured leaf yield of 2314 kg ha–1, grade index of 79%, nicotine content of 2.54%, and sugar content of 18.35% were noted in the treatment plot where B was applied as a foliar spray; however, in a few cases, there was no significant difference found among different methods of B application. Chloride and potassium contents were not significantly affected by any method of B fertilization. The B fertilization increased the concentration of this element in tobacco leaf, and a maximum concentration of B 48.55 mg kg–1 was noted in the foliar spray treatment. Moreover, fertilizer-use efficiency for different methods of B application revealed that foliar spray is more efficient as compared to soil application and root-dipping methods. Nutrient ratios to B such as potassium (K) / B and chloride (Cl) / B considerably decreased in tobacco leaf with increases in the concentration of B in leaves. These ratios provided some indication of the interrelationship of B with these nutrients in tobacco plants. Results also revealed that K/B and Cl/B ratios closely correlated with the grade index of tobacco leaf, and good grades of tobacco were found to be at a K/B ratio of 682 and a Cl/B ratio of 148 under the experimental conditions. The overall results indicated that the B foliar spray at the rate of 0.25 kg ha–1 significantly increased the yield, quality, and the nutrient uptake by the tobacco crop under the prevailing conditions and was more effective than other methods of B application.