Improving boron use efficiency via different application techniques for optimum production of good quality potato (Solanum tuberosum L.) in alkaline soil.

Boron (B) deficiency is a widespread problem in alkaline soils which affects yield and quality of potato but is often ignored by the growers. That's why, we compared the impact of different methods of boron application (foliar spray, fertigation and soil dressing) along with control on boron use efficiency (BUE), quality and yield of potato in alkaline soils. Boron (0.5 kg ha-1) applied as a foliar spray had significantly increased plant height, tuber per plant, tuber volume and enhanced the quality in terms of vitamin C, starch and B content of potato compared to other methods. Moreover, foliar applied B significantly improved B uptake and it use efficiency over other application methods. B concentration in tubers were strongly correlated with vitamin C and starch contents. The application methods were ranked as foliar spray>fertigation>soil dressing in term of their effectiveness towards potato yield and quality improvement. Thus, for optimum production of good quality potato, B should be applied as foliar spray at the rate of 0.5 kg B ha-1 in existing agro-climatic conditions.

Risk of heavy metals accumulation in soil and wheat grains with waste water irrigation under different NPK levels in alkaline calcareous soil.

A field study was conducted on the reuse of wastewater from Mardan city to evaluate its risk of contaminating soil and wheat grains at different NPK levels. Three irrigation sources i.e. waste water (WW), canal water (CW) and alternate waste + canal water (WW+CW) were applied to wheat (cv Atta Habib 2010) grown at 0, 50, 75 and 100% NPK levels of 120:90:60 kg N:P2O5:K2O ha-1 at Palatoo Research Farm, Amir Muhammad Khan Campus, Mardan during 2015.The results showed higher grain and biomass yields in WW irrigated plots as compared to CW at NPK levels up to 50% of recommending dose revealing supplementing nutrient requirements in deficient conditions. However, irrigation of WW at higher NPK levels especially at or beyond 75% of recommended dose tended to reduce the crop yield that could be associated with heavy metals toxicity and nutritional imbalances. The use of WW substantially increased AB-DTPA extractable Zn, Mn, Pb, Ni and Cd indicating a potential threat to soil contamination. Similarly, WW irrigated wheat had higher concentrations of these heavy metals as compared to CW which limits its use for production purposes without any remediation measures. The alternate use of CW and WW as revealed by its comparative lower contamination in soil and wheat than sole WW could be one of the possible solutions and may increase the time required for threshold soil contamination.

Evaluation of exotic oat (Avena sativa L.) varieties for forage and grain yield in response to different levels of nitrogen and phosphorous.

A field experiment was conducted during the Rabi season 2017-2018 (October-March) at the University of Agriculture, Peshawar research farm to examine the influence of different nitrogen (N) and phosphorus (P) levels on two different oat varieties: Australian and Ukrainian. The treatments included control and three levels of nitrogen and phosphorus at 30, 60, and 90 kg ha-1. The treatments were arranged in randomized complete block design (RCBD) and replicated three times. The findings showed that the oat varieties were significantly different from one another in yield and yield parameters. The Australian variety recorded higher emergence (49 plants m-2), days to emergence (15 days), days to flowering (122 days), days to maturity (145 days), plant height (142.7 cm), number of leaves (6.03 leaves plant-1), number of tillers (92.2 tillers m-1), biological yield (8,179.2 kg ha-1), and grain yield (3,725.6 kg ha-1) than the Ukrainian variety. Similarly, different N and P levels, the maximum days to emergence, days to flowering, and days to maturity were recorded in a control plot. The application of 105 kg N + 90 kg P ha-1 was statistically similar to the application of 105 kg N + 60 kg P ha-1. Maximum emergence (60 plants m-2), number of leaves (7.0 leaves plant-1), plant height (118.6 cm), number of tillers m-1 (102.6), biological yield (9,687.5 kg ha-1), and grain yield (4,416.7 kg ha-1) were determined in Australian variety. Based on the findings of this study, the Australian variety performed better in terms of yield and yield components and the application of N and P fertilizers at the rate of 105 kg N + 60 kg P ha-1 produced the best results in both oat varieties.

Comparing the phosphorus use efficiency of pre-treated (organically) rock phosphate with soluble P fertilizers in maize under calcareous soils.

In calcareous soils, phosphorus (P) availability to plant is impaired due to the formation of insoluble complexes with calcium and magnesium. Therefore, this study was executed to compare the P use efficiency (PUE) of four different P sources [rock phosphate (RP), acidulated rock phosphate (ARP), single super phosphate (SSP) and di ammonium phosphate (DAP)] alone or pre-treated with organic amendments (farm yard manure (FYM) enriched compost, simple compost and humic acid (HA)) along with control in maize crop under calcareous soils. All treatments irrespective of P sources received 90 kg P2O5 ha-1. Phosphorus application regardless of its sources and combination with organic amendments significantly improved maize growth, yield as well as P uptake and PUE. Rock phosphate when applied alone was recorded inferior but its performance significantly improved with compost or its pre-addition with FYM and HA, that further enhanced upon acidulation. Maize grain yield increased by 21, 22.2, 67.9 and 94% with RP, ARP, ARP enriched compost and ARP+ compost respectively, over control. Similarly, PUE of DAP improved from 31.7 to 43.1 and 39 with sample and enriched compost correspondingly. Post-harvest soil and grain P were at par for SSP, ARP and DAP alone or in conjugation with organic amendments when averaged across the amendments. These results suggested that pretreatment of P sources with organic amendments is an economical and more feasible approach to improve maize yield and PUE. Moreover, on-farm acidulation of RP may give at par results with SSP and DAP with cheaper rate and hence recommended for P management in maize in alkaline calcareous soils.

Metal accumulation potential, human health risks, and yield attributes of hundred bread wheat genotypes on irrigation with municipal and remediated wastewater.

This study was carried out to screen historical diversity panel of bread wheat against municipal wastewater (MW) and remediated wastewater (RW) irrigation to find tolerant and sensitive genotypes and their impact on yield attributes. The experiment was conducted in randomized complete block design (RCBD) with three water treatments, i.e., tap water (TW), RW, and MW. Yield attributes, health risk assessment, water and soil chemistry were recorded. Principal component analysis (PCA) was used to identify tolerant and sensitive genotypes of wheat on the basis of metal accumulation. Metal accumulation in grains increased in pattern K > Fe > Zn in all irrigation treatments. Tolerant genotypes in MW showed lowest hazard quotient (HQ) and hazard index (HI) values (adults 0.62; children 0.67) for Fe and Zn as compared to sensitive genotypes (adults 1.53; children 1.70). However, HI values in sensitive and tolerant genotypes of RW were recorded < 1. Mean values of yield attributes, i.e., plant height, spike length, spikelet per spike, grains per plant, biological yield, grain yield, and thousand kernel weight, were recorded in pattern, i.e., MW > RW > TW. In this study, yield attributes and human health are affected in both cases of higher and lower concentration of Fe and Zn metal. It is suggested that tolerant genotypes can prove useful for cultivation in areas receiving MW and also provide molecular breeding opportunities for seeking tolerance against metal stresses.

Phosphorus Nutrient Management through Synchronization of Application Methods and Rates in Wheat and Maize Crops.

Management of inorganic fertilizer is very important to obtain maximum crop yield and improved nutrient use efficiency in cereal crops. Fixation of phosphatic fertilizers in alkaline soils due to calcareousness is one of the major hurdles. It induces phosphorus nutritional stress that can decrease the yield of maize and wheat. Selection of a suitable application method and proper stage of crop for phosphorus (P) fertilizer has prime importance in better uptake of P and crop production. Among different application methods, soil and foliar application are widely adopted. In wheat and maize, knee height + tasseling and stem elongation + booting are critical stages towards P deficiency. That is why field trials were conducted to evaluate the supplemental effect of foliar P on maize and wheat yields. For that, 144 mM KH2PO4 was applied as foliar at knee height + tasseling and stem elongation + boot stages in maize and wheat, respectively. Soil application of 0, 20, 40 and 60 kg P ha-1 was done through broadcast and band methods. Results showed that foliar spray of 144 mM KH2PO4 at knee height + tasseling and stem elongation + boot stages in wheat and maize significantly enhanced grains yield and phosphorus use efficiency (PUE) where P was applied as banding or broadcast at the time of sowing. A significant decreasing trend in response to increasing soil P levels validated the efficacious role and suitability of foliar P. In conclusion, the use of P as foliar at knee height + tasseling and stem elongation + boot stages is an efficacious way to manage P fertilizer.