An analysis of the effects of nutrient supply on the growth of potato crops
Fertilizer nitrogen did not delay tuber initiation by the potato variety King Edward in the field, but slowed the early growth of tubers. Later, N hastened tuber growth and the largest amounts prolonged it. Leaf and stem growth were increased by N from an early stage. Leaf area index (L) reached maxima of 2.5 to 3.0 with the largest amounts of N, and 1.0 with no nitrogen: L decreased after late July, faster with increased N, and only the largest amount prolonged the life of the haulm. N increased leaf area duration (D) by up to 125% in both years. D was 21% greater in 1964 than 1963, and net assimilation rate in August and September was larger; consequently mean yield was 50% more in 1964. Uptake of nitrogen and N % of dry matter were increased by increasing nitrogen. The N % of tuber dry weight remained constant or increased slightly from about 2 weeks after tuber formation, while N % of the leaves and stems decreased rapidly, and much N was transferred from tops to tubers. The 1964 results suggest that tuber growth depends on continued nitrogen uptake by the plant. 
The Nature of the Stimulation of Fungal Growth by Potato Extract
Growth of four fungi on a medium of potato tuber extract and glucose was considerably higher than on a defined medium of glucose, asparagine, mineral salts, biotin and thiamine. Modification in turn of the carbon, nitrogen and growth factor components of the defined medium to resemble the extract medium did not indicate that any single component was responsible for growth stimulation; stimulation appeared to be due to the combined effects of all components. A synthetic medium of glucose, citric acid, amino acids, mineral salts and growth factors resembled the extract medium in composition and approached it in the ability to support growth of the test fungi. 
An analysis of growth of the potato crop
Linear relationships between both total and tuber dry-matter yields and the amount of radiation intercepted by potato crops are demonstrated. Their existence suggests that, in the absenceof disease and drought, the essential objective in the production of this crop is to maximize radiation interception. This paper critically assesses the influence of factors which the grower can control on light interception and estimates potential yields for specific environments. The implications of this analysis for growers, breeders, research and the whole industry are discussed. 
Comparing Liquid and Solid Media on the Growth of Plantlets from Three Kenyan Potato Cultivars
Tissue culture has been used to produce high quality and clean planting material. In addition to viral elimination, tissue culture offers other advantages such as rapid multiplication of seed stock for basic seed production within a short period of time. The method is also useful for germplasm conservation. Although, in-vitro multiplication of potato was started 40 years ago and is promising, extensive use in developing countries has been limited by the high costs of media. There is thus need to explore cheaper alternatives without compromising on quality of in -vitro plantlets. A study was carried out to compare the effects of the liquid medium and solid medium on performance of three popular Kenyan potato cultivars i.e. Dutch, Kenya Sifa and Tigoni. Liquid medium consisted of Murashige and Skoog medium supplemented with normal vitamins and sucrose while solid medium consisted of the same chemicals into which phytagel were added to solidify the medium. Data taken were number of roots, nodes and leaves per plantlet over time. From the results, the liquid medium gave more roots, more nodes and more leaves per plantlet than the solid medium. The results therefore indicated that liquid media have a significant effect on the plant growth. In addition, liquid medium was found to be cheaper than solid media by USD 1.65. It appears more economical to use liquid media than solid media for in vitro micro-propagation of potato. However, the experiment needs to be repeated especially with different potato cultivars so as to come up with useful recommendations. 
Influence of Main Stem Density on Irish Potato Growth and Yield: A Review
Our review confirms that stem density is affected by seed factors, seedbed conditions and planting methods. Physiologically old seed tubers develop into a ‘weak’ stem density. A loose friable soil that is warm and moist increases sprout emergence leading to a high stem number per hill. This high stem density can be achieved through the use of large seed tubers at planting. The greater the stem densities the higher the yield since more tubers are obtained per plant. An increase in inter stem competition associated with high stem desnity results in a decrease in harvestable tuber weight and size. However, our findings were inconclusive on the influence of varietal differences and planting depth on stem density. The influence of stem density on tuber specific gravity is also yet to be fully understood. We reiterate that producers for ware consumption should aim for low stem populations per hill while conventional seed producer are encouraged to take advantage of higher stem densities. 
 Dyson, P.W. and Watson, D.J., 1971. An analysis of the effects of nutrient supply on the growth of potato crops. Annals of Applied Biology, 69(1), pp.47-63.
 Beever, R.E. and Bollard, E.G., 1970. The nature of the stimulation of fungal growth by potato extract. Microbiology, 60(2), pp.273-279.
 Allen, E.J. and Scott, R.K., 1980. An analysis of growth of the potato crop. The Journal of Agricultural Science, 94(3), pp.583-606.
 Mbiyu, M., Muthoni, J., Kabira, J., Muchira, C., Pwaipwai, P., Ngaruiya, J., Onditi, J. and Otieno, S. (2011) “Comparing Liquid and Solid Media on the Growth of Plantlets from Three Kenyan Potato Cultivars”, Journal of Experimental Agriculture International, 2(1), pp. 81-89. doi: 10.9734/AJEA/2012/715.
 Shayanowako, A., Mangani, R., Mtaita, T. and Mazarura, U. (2014) “Influence of Main Stem Density on Irish Potato Growth and Yield: A Review”, Annual Research & Review in Biology, 5(3), pp. 229-237. doi: 10.9734/ARRB/2015/9973.