Title:

Productive performance of buffaloes in Peshawar under farm conditions

Hamid Ullah Khan, Abdur Raziq, Mohammad Ilyas Khan, Mehtabuddin and Sher Bahadar Khan

A study was carried out to know the productive performance of buffaloes maintained at Livestock Farm of NWFP Agricultural University, Peshawar, Pakistan. The data of buffalo herd was analyzed on the basis of daily, morning, evening and monthly milk yield as well as in different seasons of the year. The average highest and lowest milk production was found from 6-9 litres and 4-5 litres daily per buffalo. Morning yield was found slightly higher than evening during some months. The season on individual yearly basis did not show uniform pattern of highest yield trend but the comparative analysis on cumulative basis (including all seasons of all years) showed highest trend in summer (77.25 litres), followed by autumn (71.07 litres), spring (68.9 litres) and winter (63.72 litres). It was concluded from the present study that the milk production of buffaloes can be maintained at their maximum potential provided some good management practices are established at the farm e.g. deworming in regular intervals, feeding balanced ration and concentrates, ample quantity of drinking water and special care for seasonal requirement of the species both in terms of feeding and management.

Effect of washing and media on the germination of Papaya seeds

Okeyo Angeline and G. Ouma

Studies were carried out at Maseno University, Kenya to investigate the effect of media and seed washing on the germination and subsequent growth of Papaya (C. Papaya) seedlings. Seed extraction was carried out from the fruit then flotation test was carried out to determine viability of the seeds followed by application of the treatments which were washing half the seed lot to remove the gelatinous material and leaving the other lot unwashed. Two types of media were used namely sand and topsoil and were placed separately in pots and planting the seeds commenced with the washing and non-washing of the seeds on 17th February 2007. The pots were then placed at the shade house, which allowed 70% light. The treatments were, T1 (unwashed seeds planted in sand), T2 (washed seeds planted in Sand) T3 (unwashed seeds planted in topsoil) T4 (washed seeds planted in topsoil. The experimental design was completely randomized (CRD) replicated four times. Data taken were number of germinated seeds after four weeks from the first emergence, root length, leaf number, leaf area, stem diameter and plant height. Data was subjected to analysis of variance (ANOVA) and mean separation using L.S.D at 5% significance level. The results showed that washing affected or increased germination in sand only but it also increased the growth of the seedlings in topsoil. It is concluded that Papaya seeds should be washed and soaked before sowing to enhance germination.

Pathogenicity association in xanthomonas oryzae pv. oryzae- the causal organism of rice bacterial blight disease

D. Nayak, M. L. Shanti, L. K. Bose, U. D. Singh and P. Nayak

Pathogenicity of the isolates of Xanthomonas oryzae pv. oryzae (Xoo), the incitant of rice bacterial blight disease, collected from different rice growing states of India, were analyzed by calculating (i) virulence frequency (VF) on each host genotype, (ii) pathogenicity association coefficient (PAC) and (iii) virulence association coefficient (VAC) of all possible combinations of two host genotypes, in different sets of rice genotypes involving differential varieties, near isogenic lines (NIL) and gene pyramids each possessing known genes for resistance. Based on the host-pathogen interactions, 4-11 virulence factors could be recognized in the 52 bacterial isolates viz. v-1, 2, 3, 4, 5, 6, 7, 10, 11, 12 and 13 which were effective against 11 Xa genes conferring resistance to Xoo. A total number of 0-7 avirulence gene factors could also be recognized in the bacterial isolates. The combination of host genes for resistance, which can be effectively deployed in disease control strategy, was characterized by high PAC: low VAC with widest difference between the two and least difference between one and PAC (1-PAC) accompanied by low virulence frequency. The gene combinations responsible for rapid disease spread, which warrant immediate withdrawal from a specific locality, could be characterized by high PAC: high VAC and zero to low difference between PAC and VAC as well as 1-PAC accompanied by high VF for both the genotypes. Such analysis of extensive pathogenicity survey data on large number of isolates representing any particular region would help in taking decision on deployment of desired gene combinations for effective disease control, withdrawal of varieties possessing undesirable gene combinations, breeding varieties possessing resistance genes for specific region and development of NILs.

Disease progress curves in the rice blast pathosystem compared with the logistic and Gompertz models

N. K. Mohapatra, A. K. Mukherjee, A. V. Suriya Rao and P. Nayak

Comparison of the linear coefficients from the regression analysis of 307 blast (Pyricularia grisea) disease progress curves of 42 rice genotypes, tested over a period of nine seasons, were made by fitting into the logistic and Gompertz models. The regression parameters Y- intercept (a), regression coefficient (b), its standard error (SEb), coefficient of determination (R2) and the time required for the disease to reach specific level of severity (T50) were estimated. The estimates of the linear coefficients following Gompertz model, revealed lower values of b, SEb and negative 'a'; higher values of T50 as well as R2 compared with those by logistic model. In general, the logistic apparent infection rates were higher than the Gompertz rates, the differences being wider for the slow-blasting genotypes compared with the fast-blasting genotypes. The lower Gompertz infection rates accompanied with low negative ‘a' values, resulted in higher T50 values, compared with the respective lower estimates  through logistic model. Both b and T50 values estimated by Gompertz model were more consistent among the slow-blasting genotypes over seasons. Out of the 307 disease progress curves, 91.2 % fitted well in to the logistic model and 90.8% in to the Gompertz model, thus suggesting that both the models fit well in to the rice blast pathosystem. The estimates of T50 were proportional to the corresponding apparent infection rates in both the models. The benefit from sanitation in terms of the epidemic to reach 0.5 level, was estimated to be 21 and 47 days following logistic and Gompertz models, respectively.

Phenotypic correlation analysis of elite F_3:4 Brassica populations for quantitative and qualitative traits

Sajid Khan, Farhatullah and Iftikhar H. Khalil

Six F_3:4 derived inter-specific Brassica populations along with three checks were evaluated for phenotypic correlations for qualitative and quantitative characters at NWFP Agricultural University, Peshawar during 2005-06. A randomized complete block design with four replications was used. Higher significant values of association were observed for day to flowering with pods raceme^-1 (0.90) and significant association with glocusinolate (-0.67), primary braches plant^-1 show high significant correlation with pod length (-0.93), seed pod^-1(-0.88) and yield ha^-1(-0.78) and significant correlation with linolenic acid (0.68). Pod length highly significantly related with seed pod^-1(0.93), yield ha^-1(0.83) and linolenic acid (-0.83). The association of seed pod^-1 was observe high significant with yield ha^-1 (0.88) and linolenic acid (-0.89). Generally, low correlation was observed among different traits; however some of the related characters like days to flowering, pods raceme^-1, pos length, plant height, seed pod^-1, yield hac^-1, oleic acid, and moisture were highly significantly and positively correlated with each other as compares to the remaining traits which are negatively and non-significantly correlated with each other. So selections for such traits are useful for yield and quality improvement.