Consistency of long-term marketable yield of carrot and onion cultivars in muck (organic) soil in relation to seasonal weather

Abstract

Tesfaendrias, M. T., McDonald, M. R. and Warland, J. 2010. Consistency of long-term marketable yield of carrot and onion cultivars in muck (organic) soil in relation to seasonal weather. Can. J. Plant. Sci. 90: 755Á765. To identify carrot and onion cultivars that provide consistent marketable yields, we tracked the yields of five fresh market carrot [Daucus carota L. subsp. sativus (Hoffm.) Arcang.] and six onion (Allium cepa L.) cultivars for at least 13 yr. Relationships between longterm weather variables and marketable yields were also investigated. The effects of cultivar, year and cultivar)year interactions on yield of carrots and onions were assessed. Cultivar and year had significant effects on carrot and onion yields, while the interaction was significant in only one of four data sets of carrot yield. Carrot cv. Cellobunch (95.4 t ha(1 ) and onion cv. Corona (74.1 t ha(1 ) had the highest mean marketable yields over the years studied. There was a slight positive correlation between mean yield of the assessed carrots and maximum temperatures in September (r 00.44). Mean carrot yield was also somewhat negatively correlated with total rainfall in July (r 0(0.43) and with number of days with rain in August (r 0(0.43) and September (r 0(0.44). Most onion cultivars showed stronger relationships between marketable yield and various weather patterns. Marketable yield of onions increased with an increase in the number of days with rainfall in June (r 00.57). The mean marketable yield of the six onion cultivars decreased in relation to temperatures ]308C in June (r 0(0.55) and August (r 0(0.53). The mean yield of all the onions in the trials was negatively correlated (r 0(0.78) with growing degree days (base 58C, May to August). The results indicated that the data from long-term cultivar trials can be used to identify cultivars that yield well despite seasonal variations in weather. Le rendement moyen de carottes pre´sente aussi une le´ge`re corre´lation ne´gative avec l'importance des pre´cipitations en juillet (r 0(0,43) ainsi qu'avec le nombre de jours de pluie au mois d'aouˆt (r 0(0,43) et en septembre (r 0(0,44). Pour la plupart des varie´te´s d'oignon, on note de fortes relations entre le rendement commercialisable et diverses conditions atmosphe´riques. Ainsi, le rendement commercialisable des oignons augmente avec le nombre de jours de pluie en juin (r00,57). Le rendement commercialisable de six cultivars d'oignons diminue aussi quand la tempe´rature est e´gale ou supe´rieure a`308C en juin (r 0(0,55) et en aouˆt (r0(0,53). Lors des essais, le rendement moyen des oignons pre´sentait une corre´lation ne´gative (r 0(0,78) avec le nombre de degre´s-jours de croissance (tempe´rature de base de 58C, de mai a`aouˆt). Les re´sultats indiquent qu'on peut se servir des re´sultats des essais a`long terme sur les cultivars pour identifier les varie´te´s donnant un bon rendement en de´pit des variations climatiques saisonnie`res.

Temperature extremes: Effect on plant growth and development

“…In these plants, there was an increased sensitivity heat stress 7 to 15 days before anthesis, coincident with pollen development. Subjecting plants to a more intense heat stress (generally greater than 4°C above optimum) resulted in severe yield loss extending to complete crop failure (Ghosh et al, 2000;Sato et al, 2000;Kadir et al, 2006;Gote and Padghan, 2009;Tesfaendrias et al, 2010). Tomatoes under heat stress fail to produce viable pollen while their leaves remain active.…”

“…When plants are subjected to mild heat stress (1°C to 4°C above optimal growth temperature), there was moderately reduced yield (Sato, 2006;Timlin et al, 2006;Wagstaffe and Battey, 2006;Tesfaendrias et al, 2010). In these plants, there was an increased sensitivity heat stress 7 to 15 days before anthesis, coincident with pollen development.…”

Performance of some Asian carrot (Daucus carota L. ssp. sativa Hoffm.) cultivars under Ethiopian conditions: Carrot and seed yields

“…The marketable yield of most of the cultivars in this trial was within the 8.4-26 t ha −1 range recorded in 15 commercial carrot cultivars by Brandenberger et al (2007). In contrast, Tesfaendrias et al (2010) evaluated 24 cultivars for many years and found significant environment by cultivar interaction and recorded marketable yields of 78-95 t ha −1 from the top six cultivars. The maximum marketable yields of Nantes and DZARC-5 recorded in Experiments 1 and 3 were 26-55 t ha −1 lower than the results of Tesfaendrias and coinvestigators, which might be due to differences in cultivar, soil and level of management.…”

Climate Change: Challenges for Future Crop Adjustments

“…When plants are subjected to mild heat stress (1-4 C above optimal growth temperature), there was moderately reduced yield [38][39][40][41]. In these plants, there was an increased sensitivity to heat stress 7-15 days before anthesis, coincident with pollen development.…”

“…In these plants, there was an increased sensitivity to heat stress 7-15 days before anthesis, coincident with pollen development. Subjecting plants to a more intense heat stress (generally greater than 4 C increase over optimum) often resulted in severe yield loss up to and including complete failure of marketable produce [33,[41][42][43][44]. There is evidence that temperature effects on yield loss vary among crops and among cultivars within crops.…”