Effects of Frequency of Sprinkling With Saline Waters Compared With Daily Drip Irrigation1
- Leon Bernstein and
- L. E. Francois2
We previously attributed the injury to bell peppers (Capsicum frutescens) by sprinkling them with saline water to flushing into the root zone of salts accumulated at the soil surface rather than to foliar salt absorption. These two possible mechanisms of salt injury have now been studied further by observing the effects of sprinkling frequency and the related degree of surface salt accumulation. Bell peppers in small field plots were sprinkled every 2.3, 3.5, and 4.75 days (average intervals for each treatment) with low-salt (450 mg/liter) and medium and high-salt waters (1,000 and 2,000 mg/liter of added NaCl + CaCl2, respectively). Three additional plots were drip irrigated daily with the three waters for comparative purposes. Soil salt distributions, foliar salt contents, and bell pepper yields were determined.
Sprinkling with the low-salt water and drip irrigation with all three waters caused no leaf damage. Plants sprinkled every 2.3 days with the two saline waters suffered more leaf burn and produced lower yields than plants sprinkled less often. Sprinkling with the medium-salt water reduced yields appreciably only at the highest frequency (2.3 days) but sprinkling with the high-salt water reduced yields more than 50% at all sprinkling frequencies, compared to a yield loss of only 14% by drip irrigation with this water. Since sprinkling with the medium-salt water caused no observable osmotic shock by salt flushing, injury and yield loss appear to be related primarily to foliar salt absorption. Sprinkling with saline waters appears to induce sensitivity to sodium and chloride in bell pepper plants as it does in other species that do not appear sensitive to these ions when surface irrigated.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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