Repercussion of photosynthetic variables and related enzymes under influence of sodium dihydrogen orthophosphate and sodium sulphatewith two modes of gibberellic acid application

An experiment was carried out to investigate whether the application of gibberellic acid (GA) along with NaH2PO4 and/or Na2SO4 could ameliorate photosynthetic variables and enzymes in chickpea cultivar DCP 92-3 without compromising the nitrogen fixing activity. Before, sowing the seeds of chickpea were soaked for 8 h in 10-6MGA. 60 and 70 days after sowing (DAS), the plants were sprayed with 10-6MGA along with 2 kg P and /or S/ha in two equal splits. Performance of the crop was assessed in terms of chlorophyll content (Chl), net photosynthetic rate (PN), stomatal conductance (gs), carbonic anhydrase activity (CA) and one most significant N-fixing enzyme, NR. Treatment (16) SGA+FGAPS proved best, it enhanced Chl content by 46.16% and 48.84% PN by 64.24 and 65.37%, NR by 22.37% and 22.46% respectively at 90 and 100 DAS. CA at 100 DAS only and gs at both stages of sampling found non-significant. Moreover, CA enhanced by 64.56% at 90 DAS also.

Effects of phosphates and citrates on sediment formation in UHT goats' milk

Sediment formation was investigated during UHT treatment of goats' milk, subjected to indirect treatment at 140°C for 2 s, with upstream homogenisation. Stabilisers evaluated were sodium hexametaphosphate (SHMP), trisodium citrate (TSC), disodium hydrogen orthophosphate (DSHP), and sodium dihydrogen orthophosphate (SDHP). With no added stabiliser, goats' milk produced a heavy sediment on UHT treatment. Addition of SDHP reduced pH, had little effect on ionic calcium and did not substantially reduce sediment. However, addition of SHMP, DSHP and TSC each reduced ionic calcium, increased ethanol stability and reduced sediment. Following stabiliser additions, there was a good correlation between ethanol stability and ionic calcium (R2=0·85) but not between ethanol stability and pH (R2=0·08). Overall, reducing ionic calcium reduced the amount of sediment formed for all these three stabilisers, although there was no single trend line between sediment formation and ionic calcium concentration. Sediment formation was not well correlated with pH for TSC or for SHMP, but it was for DSHP, making it the only stabiliser where sediment formation correlated well both with ionic calcium and pH, which might account for its effectiveness at higher ionic calcium levels. Sediment was much reduced when the temperature was reduced from 140°C to 125°C and 114°C. There were no further changes in sediment on storage for two weeks. Analysis of the sediment showed that it was predominantly fat and protein, with a mass ratio ranging between 1·43:1 and 1·67:1. Its mineral content was usually less than 5% of dry weight. The maximum amounts of P and Ca were found to be 2·32% and 1·63%, respectively.

The buffering capacity of caecal digesta exceeds that of rumen digesta from sheep fed pasture or roughage diets

The buffering capacities of caecal and rumen digesta of sheep on different diets were determined by titration with lactic, acetic, and hydrochloric acids, and certain factors affecting the buffering capacity of rumen digesta were studied. Both rumen and caecal digesta had maximal buffering capacity at pH 6·5–6·0. The buffering capacity of caecal digesta was nearly double (P < 0·001) that of rumen digesta. The rumen digesta from sheep fed oaten chaff had a buffering capacity 21% higher (P < 0·05) than that of sheep grazing green pasture. This was reduced (P < 0·05) by one-third following ruminal infusions of glucose, lactic, or acetic acid to induce acidosis. Diet did not significantly affect the buffering capacities of rumen and caecal digesta. However, the buffering capacities of rumen and caecal digesta from pasture-fed sheep that had been fasted for 24 h were significantly greater (P < 0·001) than those for sheep that had not been fasted (62 and 18%). The buffering capacity determined using HCl was always less than that for lactic or acetic acid. This may be due to the lower pKa for HCl and the fact that there is no evidence that HCl undergoes inter-conversion through fermentation that the organic acids may undergo. The addition of carbonate or phosphate buffer significantly increased (P < 0·05) the buffering capacity of rumen and caecal digesta. The sodium bicarbonate and sodium carbonate (NaHCO3 and Na2CO3) system played a more effective buffering role than the sodium dihydrogen orthophosphate and disodium hydrogen orthophosphate (NaH2PO4 and Na2HPO4) system in the rumen digesta.