Optimal pot size for growing sugarcane

Under certain circumstances, the use of pots to grow plants becomes necessary, for example when plants need to be contained or treatments applied. Sugarcane is a large plant, growing as tall as 150–600 cm and, while most roots grow within the top 60 cm of soil, they can also extend up to and past 100 cm. While sugarcane can be propagated in small 1 L pots, the resulting plant is not comparable to field-grown cane. This experiment tested three different pot sizes to determine what size produced plants that were most comparable to field-grown plants. Pots containing 35, 52 and 70 L of soil were planted with varieties Q208 A , Q234 A and Empire. The plants were grown outside to ensure that growth was not limited by light levels. Stalk number, height, diameter and weight were measured after 16 months growth. Differences in growth related to pot size were seen for some variety-pot size combinations. Where there was a similar result to field-grown plants, it was always with plants grown in the 52 L pots: stalk number for Empire was highest in the 52 L pots, stalk diameter was larger in the 52 L pots for Q113, the stalk weight of the Q113 plants grown in 52 L pots was similar to that seen in the field, and for Q208 A grown in 52 L pots the stalk number was similar to that measured in the field. Hence, we conclude that the 52 L pots provide growth conditions that are the best proxy for field growth. Surprisingly, the larger root volume available in the 70 L pots did not improve plant growth. The ranking of the varieties remained the same for each phenotype regardless of the pot size, demonstrating that pots can provide an acceptable model for field-grown research. Key words Pot, field, growth conditions