Effect of pH on germination and seedling growth of maize.

Abstract

Soil pH is one of the most important limiting factors for crop cultivation, including maize. About 30-40% of the world's arable land is acidic, and over a billion ha is alkaline. Today, there are 205 million ha of arable land under maize in the world, so it ranks third in area after rice and wheat. Maize hybrids have wide genetic variability and high pH tolerance. We tested the tolerance of maize hybrids seedlings of ZP 4708 and ZP 5797 to pH 5, 6, 7, and 8. Results showed that hybrid ZP 4708 has a higher adaptability to low and high pH, due to the higher value of germination energy (GE), shoot length (ShL), shoot fresh weight (ShFW), shoot dry weight (ShDW), germination rate index (GRI), and seedling vigor index (SVI) than hybrid ZP 5797. Results further showed, on average for hybrids, that pH 5 and pH 8 significantly decreased the GE, root length (RL), ShL, root fresh weight (RFW), ShFW, root dry weight (RDW), shoot fresh weight (ShDW), and SVI. These parameters did not differ significantly between pH 6 and pH 7. Seed germination was not affected by the pH, indicating that the seed vigor of both hybrids supports full germination potential. However, it could be expected that exposure to the lowest and highest pH values of the medium could affect seedlings growth in the field conditions, even though germination is high. SVI showed a positive and significant correlation with all investigated parameters, except germination (G) and relative seedling water content (RSWC).

pH zemlji ta je jedan od va nih ograni avajućih faktora za gajenje useva, a samim tim i kukuruza. Oko 30-40% svetskih obradivih povr ina je kisele reakcije, a preko milijardu ha je alkalno. Danas je u svetu 205 miliona ha obradivih povr ina pod kukuruzom, tako da on zauzima treće mesto po povr ini posle pirin a i p enice. Hibridi kukuruza imaju iroku genetsku varijabilnost i toleranciju za pH. Ispitivali smo toleranciju klijanaca novih hibrida kukuruza ZP 4708 i ZP 5797 na pH 5, 6, 7 i 8. Rezultati su pokazali da hibrid ZP 4 08 ima bolju sposobnost adaptacije na nisku i visoku pH vrednost jer je imao veću energiju klijanja (EK), du inu stabla (DS), sve u masu stabla (SvMS), suvu masu stabla (SuMS), indeks klijavosti (IK) i vigor indeks (VI) od hibrida ZP 5797. Rezultati su dalje pokazali, u proseku za hibride, da su niski (pH 5) i visoki pH nivo medijuma (pH8) zna ajno smanjili EK, du inu korena (DK), DS, sve u masu korena (SvMK), SvMS, suvu masu korena (SuMK), SuMS i VI. Ovi parametri se nisu razlikovali između tretmana pH 6 i pH . pH medijuma nije uticala na klijanje semena to ukazuje da snaga semena oba hibrida podr ava pun potencijal klijanja. Međutim, izlaganje najni im i najvi im pH vrednostima medijuma je dovelo do toga da nije moguće o ekivati jake klijance, iako je klijavost visoka. VI je pokazao pozitivnu i zna ajnu korelaciju sa svim ispitivanim parametrima, osim sa klijanjem semena i relativnim sadr ajem vode u klijancima.