Dartnall, WJ 1986, 'A pump.'.
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A borehole pump which avoids the use of a piston sealing within a cylinder, comprises a tubular pump body closed at its lower end by a non return inlet valve and slidably supporting through a seal at its upper end a reciprocating riser pipe likewise closed at its lower end by a non return outlet valve. An upward stroke of the riser pipe draws fluid into the pump body via the inlet valve whilst downward movement expels fluid from the body via the outlet valve and through the riser. (A.E.H.)
Pearson, CJ & Jacobs, BC 1986, 'Elongation and retarded growth of rice during short-term submergence at three stages of development', Field Crops Research, vol. 13, no. C, pp. 331-343.
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Rice (Oryza sativa L.) cultivars IR36 and IR42 were grown under upland or lowland conditions and then submerged partially or completely for 8 days at the seedling (6-leaf) stage, tiller elongation or booting. Partial or complete submergence at any of the three stages of development reduced the rate of weight gain or caused loss of weight from plant organs in the order root > stem > leaf. Submergence at all stages caused elongation of leaf sheaths and stems (as measured to the uppermost ligule); elongation occurred primarily in response to water at the base of the stem rather than at the shoot apex. IR42 elongated its leaf lamina more than IR36. IR36 maintained a greater number of tillers than IR42. Complete submergence at the tillering stage caused a small reduction (20%) in number of grains in the mainstem panicle of IR36 and a larger reduction (40%) in IR42; it had little or no effect on total grain number of IR36 whereas it reduced the total grain number of IR42. Grain number was positively correlated with change in stem weight during submergence, suggesting that grain number may have been reduced by submergence causing a carbohydrate deficiency during primordia development. Submergence increased the weight of attached dead leaves and reduced root length. Partial submergence reduced, but did not stop, the uptake of nitrogen. Concentrations of N, Mn and K tended to increase (except in leaves) during submergence, relative to 'control' plants. There were statistically significant interactions between cultivar and submergence in only 10% of analyses. Nonetheless IR36 did appear to have greater tolerance than IR42 to short-term submergence, whereas greater lamina elongation may cause IR42 to be better adapted than IR36 to prolonged, partial submergence. © 1986.
